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N.C.  STATE  UNIVERSITY     O.H.  HILL  LIBRARY 


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THIS  BOOK  IS  DUE  ON  THE  DATE 
INDICATED  BELOW  AND  IS  SUB- 
JECT TO  AN  OVERDUE  FINE  AS 
POSTED  AT  THE  CIRCULATION 
DESK. 


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100M/7-87— 871203 


17510 


Ube  iRural  UcxUBooh  Series 

Edited  by  L.  H.  BAILEY 


THE  CORN   CROPS 


€\}t  Eural  KntBoolx  Scries 

Lyon  and  Fippin,  Pkincifles  of  Soil  Man- 
agement. 
G.  F.  Warren,  Elements  of  Agriculture. 

A.  R.  Mann,  Beginnings  in  Agriculture, 
J.  F.  Duggar,  Southern  Field  Crops. 

B.  M.    Duggar,    Plant    Physiology,    with 
Special  Reference  to  Plant  Production. 

G.  F.  Warren,  Farm  Management. 

M.    W.    Harper,    Animal    Husbandry    for 

Schools. 
E.  G.  Montgomery,  The  Corn  Crops. 
H.  J.  Wheeler,  Manures  and  Fertilizers. 


(Frontispiece) 


TYPICAL  PLANTS  OF  DENT  CORN. 


THE   CORN   CROPS 


A   DISCUSSIO:?^   OF   MAIZE,   KAFIRS,  AND 

SORGHUMS  AS  GROWN  IN  THE 

UNITED  STATES  AND  CANADA 


,     ,'?.'  BY 

E.   G.   MONTGOMERY 


PROFESSOR  OF  FARM  CROPS  IN  THE  NEW  YORK 

STATE  COLLEGE  OF  AGRICULTURE  AT 

CORNELL  UNIVERSITY 


N£to  gork 

THE   MACMILLAN    COMPANY 

1916 

All  rights  reserved 


COPYBIGHT,   1913, 

By  the  MACMILLAN  COMPANY. 


Set  up  and  electrotyped.     Published  August,  1913.     Reprinted 
July,  1915;  February,  August,  1916. 


NorbJooU  i^resgs 

J.  S.  Gushing  Co.  —  Berwick  &  Smith  Co. 

Norwood,  Mass.,  U.S.A. 


PREFACE 

In  planning  a  course  of  study,  the  author  must  needs  lay- 
out a  working  plan.  He  should  know  the  philosophy  of  his 
subject  and  its  relation  to  other  sciences.  Field  crops  like 
other  applied  sciences  has  little  pure  science  of  its  own,  but 
is  rather  based  on  other  sciences.  The  subject  is  not  erected 
so  much  as  a  superstructure  on  other  sciences,  but  rather 
moves  in  a  progressive  way,  between  them,  abstracting  such 
elements  from  each  as  contribute  to  the  art  of  producing  the 
crop  under  consideration. 

The  outline  on  page  vi  is  an  attempt  to  illustrate  the  log- 
ical order  of  study  and  relation  of  other  sciences  to  the 
study  of  Crop  Production. 

The  outline  below  indicates  that  a  knowledge  of  all  the 
"earth  sciences"  is  fundamental  to  a  study  of  crop  produc- 
tion, hence  a  student  should  have  a  general  course  in  all 
these  sciences  with  special  emphasis  ou  botany  (physiology 
and  ecology)  and  chemistry. 

In  regard  to  a  particular  crop  like  maize,  this  knowledge 
needs  special  interpretation  and  application,  which  is  the 
function  of  field  crops  instruction. 

The  ability  to  yield  with  our  ordinary  crops  is  far  above 
the  average  yield.  With  maize  200  bushels  per  acre  have 
been  produced  under  optimum  conditions,  while  the  average 
yield  is  about  26  bushels.  Therefore  the  study  of  maize 
production  is  principally  a  study  of  those  factors  which 
serve  to  hinder  full  development,  and  thus  limit  production, 


^^^'::V^ 


w\'^ 


VI 


PREFACE 


Outline  Plan  showing  the  Relation  of  the  Sciences  to 
THE  Various  Phases  of  Crop  Production 


Department 

Character  of  Work 

Basic  Science 

GIVING  Work 

INVOLVED 

The  Plant 

1.  Botany 

Study      of      normal 

Botany 

Field  crops  treats 

plants,  their  histol- 

application to 

ogy,     physiology. 

special  crop 

etc.,     and     normal 
environmental     re- 
quirements 

Survey 

2.  Field  crops  will 

Survey  of  natural  con- 

Ecology (Botany) 

consider     the 

ditions  as  related  to 

Meteorology 

application  of 

the   normal,   under 

Geology 

the  sciences  to 

which  it  is  proposed 

(Geography) 

the  particular 

to      cultivate      the 

crop        under 

plant 

consideration 

Adaptation 

3.   (a)  Field    crops 

(a)  Adaptation   of 

(a)  Plant  breeding 

(Plant  breed- 

plant to  climate 

(natural  and 

ing) 

and  soil 

artificial    se- 
lection) 
Ecology 

(6)  Soils 

(6)  Adaptation  of  soil 

(b)  Chemistry 

to  plant 

Physics 
Bacteriology 

Protection 

4.   (a)  Field  crops; 

(a)  Farm  practice  in 

also  farm 

preparing    and 

practice 

planting    fields 

for  (6)  and 

in  order  to  pro- 

(c) 

tect    against 
weeds,  drought, 
rain,  et-c. 

(6)  Botany  (the 

(b)  Against     fungous 

Botany 

diseases) 

diseases 

(c)    Entomology 

(c)   Against  insects 

Entomology 

(the    in- 

sects) 

PREFACE  Vll 

and  the  art  of  maize  production  is  removing  or  modifying 
these  limiting  factors. 

Practically  the  whole  problem  is  involved  in  securing 
a  perfect  harmony  between  the  plant  and  its  environ- 
ment. 

Environment  may  be  classed  as  climatic  factors  and  soil 
factors.  Over  climate  we  exercise  little  or  no  control. 
Either  the  plant  must  be  adapted  to  suit  the  climate  or  its 
production  is  limited  only  to  those  regions  where  a  natural 
climate  is  found  to  which  the  plant  is  suited.  The  natural 
precipitation  is  about  the  only  factor  assigned  to  climate, 
the  effect  of  which  can  be  modified.  Where  precipitation  is 
excessive,  land  can  be  drained,  or  where  deficient,  methods 
of  storing  the  moisture  in  soil  may  be  adopted.  However, 
within  certain  limits  there  is  usually  an  optimum  rainfall 
which  favors  the  largest  production. 

Soil  environment,  however,  is  subject  to  modification  in  a 
very  large  degree.  If  proper  elements  are  present  in  the 
soil  but  in  an  insoluble  state,  solvents  may  be  added  as 
decaying  organic  matter,  or  air  be  admitted  by  tillage  and 
the  bacterial  flora  increased.  If  the  proper  mineral  ele- 
ments are  not  present  or  present  in  an  unavailable  form, 
these  elements  may  be  added  to  the  soil,  until  a  normal 
state  of  fertility  is  produced. 

After  the  conditions  of  adaptation  of  both  plant  and  soil 
have  been  fulfilled  so  far  as  practicable,  and  seed  has  been 
planted  in  suitable  soil,  it  is  then  necessary  to  protect. 
Protection  is  the  principal  reason  for  cultivation.  To  facil- 
itate cultivation,  systems  of  planting  have  been  devised,  as 
the  distribution  of  the  plants  in  rows,  drills,  or  checks,  in 
furrows  or  on  the  level  surface. 

Protection  against  insect  enemies  and  fungous  diseases  is 
also  an  important  part  of  production,  and  is  one  of  the 
reasons  for  the  practice  of  rotations. 


Vlll  PREFACE 

A  large  share  of  farm  practice  has  to  do  with  modifying 
the  soil  environment  and  protection  of  the  crop. 

THE    PHILOSOPHY    OF    CROP    PRODUCTION 

The  art  of  crop  production  is  based  on  an  application  of 
the  sciences,  (a)  to  producing  a  natural  condition  as  per- 
fectly adapted  as  possible  to  the  needs  of  some  particular 
crop,  or  (b)  the  adaptation  of  the  crop  to  certain  natural  con- 
ditions. 

The  study  of  crop  production  for  any  large  region  in- 
volves a  study  of  four  general  phases  of  the  subject,  as  : 
1.  The  plant,  its  structure,  x^hysiology,  and  normal  require- 
ments. 2.  A  general  survey  of  the  region  where  it  is  pro- 
posed to  cultivate  the  plant,  to  note  how  the  natural  conditions 
found  correspond  to  the  needs  of  the  plant.  3.  The  adapta- 
tion of  the  plant  on  the  one  hand  to  natural  conditions  and 
adaptation  of  soil  on  the  other  to  the  needs  of  the  plant. 
Maximum  production  is  obtained  when  perfect  adaptation  is 
secured.  4.  Protection  is  necessary  against  other  indige- 
nous plants,  fungous  diseases,  and  insects. 

The  treatment  of  subjects  in  the  text  follows  practically 
the  above  plan.  The  x^lan  also  allows  a  wider  use  of  the 
text  for  different  classes  of  students.  The  first  two  divisions 
are  technical  and  should  only  be  studied  by  students  who 
have  training  in  the  sciences  involved.  With  less  advanced 
students  the  work  may  begin  with  Part  III,  Adaptation. 
The  third  and  fourth  divisions  deal  with  the  more  practical 
phases  of  production  and  are  written  in  a  more  popular  style, 
this  double  use  of  the  book  being  in  mind. 

Acknowledgments.  —  For  furnishing  photographs  used 
in  illustrating  the  text,  the  author  is  indebted  to  Mr.  Carle- 
ton  R.  Ball,  Mr.  C.  W.  Warburton,  and  Mr.  C.  P.  Hartley, 
all  of  the  Bureau  of  Plant  Industry.     A  large  number  of 


PREFACE  IX 

photographs  secured  from  the  Nebraska  Experiment  Station 
have  also  been  used,  Professor  T.  A.  Kisselbach  furnishing 
several  of  these.  Also  the  Portland  Cement  Co.,  Deere  and 
Co.,  Janesville  Machine  Co.,  Planet  Jr.  Co.,  and  Sandwich 
Manufacturing  Co.  have  furnished  illustrative  material. 


E.  G.  MONTGOMERY. 


Ithaca,  N.Y., 
January  1,  1913. 


TABLE   OF   CONTENTS 

PART  I 

CORN 

CHAPTER  I 

PAGES 

Production  and  Distribution  of  Indian  Corn  .  .  .  1-11 
Kelative  importance  of  corn  and  other  crops  in  the 
world,  1  —  Corn  crop  of  the  world,  3  —  International  trade 
in  corn,  4  —  Relative  value  of  different  crops  in  the  United 
States,  6  —  Development  of  corn  production  in  United 
States,  7  —  Production  by  states,  7  —  Production  by  sec- 
tions and  market  movement,  11. 

SECTION   I 
THE   CORN   PLANT 

CHAPTER   II 
Origin  and  Classification 15-25 

Geographical  origin,  15  —  Biological  origin,  16  —  Classi- 
fication of  maize  in  groups,  20. 

CHAPTER   III 

Description  of  the  Corn  Plant 26-37 

The  root,  26  —  The  stem,  31  —  Tillers,  33  —  Leaves,  33 
—  The  flower,  36  —  The  ear,  37. 

CHAPTER  IV 

Physiology  of  Corn 38-56 

Turgidity,  39  — Tension,  40  —  Mechanical  tissue,  40  — 
The  composition  of  a  corn  plant,  42  —  The  absorption  of 
water,  45  —  The  giving  off  of  water,  45 — Assimilation, 
47  —  Growth,  48  —  Reproduction,  49  —  Pollen,  50  —  Style, 
51 — Fertilization,  52. 


XU  TABLE  OF  CONTENTS 

SECTION   II 

PRODUCTION   AS   RELATED   TO  CLIMATE 
AND  SOILS 


CHAPTER   V 

PAGES 

Relation  of  Climatic  Factors  to  Growth         .         .         .     57-67 
Relation  of  climatic  factors  to  growth,  58 — Length  of 
growing  season,  59  —  Relation  of  sunshine  to  growth,  61 
—  Relation  of  rainfall  to  growth,  64. 

CHAPTER   VI 

Relation  of  Soils  to  Growth 69-73 

Causes  of  low  production,  70  —  Classification  of  corn 
soils  in  the  United  States  according  to  productiveness,  70. 


SECTION   III 

IMPROVEMENT  AND  ADAPTATION  OF  THE 
CORN   PLANT,   AND   ENVIRONMENT 

CHAPTER  VII 

Early  Culture 77-84 

Development  of  varieties,  78  —  Early  methods  of  modi- 
fying varieties,  80  —  Natural  selection  and  acclimatization 
in  producing  varieties,  83. 

CHAPTER  VIII 

Improvement  of  Varieties     .......     85-93 

Type  of  ear,  85  —  Type  of  plant,  86  —  Systems  of  selec- 
tion, 88  —  Results  with  mass  and  pedigree  selection,  89  — 
Selection  for  composition,  91. 


TABLE  OF  CONTENTS  Xlll 

CHAPTER   IX 

PAGES 

Methods  of  Laving  out  a  Breeding  Plat       .         .         .       94-100 
How  to   conduct  a  breeding  plat,  95 — The   second 
year's   work,   98  —  Continuation  of    breeding,   several 
plans,  99. 


CHAPTER  X 

Results  with  Hybridization      ......     101-116 

Degrees  of  Relationship,  101  —  Xenia,  103  —  Mendel's 
laws,  104  —  Dominant  and  recessive  characters,  105  — 
Hybridization,  effect  on  growth,  107 — Self-fertilization, 
107  —  Pure  strains,  or  biotypes,  109  —  Crossing  biotypes, 
111  —  Crossing  varieties,  111  —  Isolating  high-yielding 
biotypes,  115. 


CHAPTER   XI 

Acclimation  and  Yield 117-121 

Effect  of  environment  on  the  corn  plant,  118  —  Effect 
of  previous  environment  on  yield,  119  — Adaptation  of 
the  soil,  121. 


CHAPTER   XII 

Cropping  System  in  Relation  to  maintaining  the  Yield 

OF  Corn 122-128 

Cropping  systems,  122  —  Restoring  production,  123  — 
Maintaining  production,  124 —  Rotations  for  corn  grow- 
ing, 127. 


CHAPTER   XIII 

Organic  Matter 129-134 

Farmyard  manure  for  corn,  130. 


XIV  TABLE   OF  CONTENTS 

CHAPTER  XIV 

PAGES 

Mineral  Matter 135-150 

Fertilizers  for  corn,  138  —  Fertilizer  mixtures  for  corn, 
142  —  When  it  pays  to  fertilize  for  corn,  144  —  Nitrogen, 
146  — Lime,  147. 

CHAPTER  XV 

Regulating  the  Water  Supply         .         .         •        .         .     151-157 
Erosion,  154  —  Drainage,  157. 


SECTIOI^  IV 
CULTURAL  METHODS 

CHAPTER   XVI 

Preparation  and  Planting         ......     161-196 

The  old  corn  stalks,  161  —  Time  of  plowing,  163  — 
Depth  of  plowing,  163  —  Subsoiling,  166  —  Preparation 
of  plowed  land,  166  —  Planting  the  seed,  methods,  168 

—  Sowing  corn  for  forage,  171  — Checking  and  drilling, 
172— Time  of  planting,  172  — Rate  of  planting,  176  — 
Adjustment  of  corn  plants,  178  —  Economic  value  of 
tillers,  179  —  Rate  of  planting  on  different  soils,  180  — 
Methods  of  distribution  of  plants,  181  —  Width  of  rows, 
182  —  Yield  of  forage,  183  —  Effect  on  composition,  183 

—  Choice  of  a  variety,  184  —  Preparing  seed  for  plant- 
ing, 190  —  Causes  of  poor  germination,  190  —  Germina- 
tion tests,  192  —  Importance  of  strong  vitality,  194  — 
Grading  seed,  196  —  Calibrating  the  planter,  195. 

CHAPTER   XVII 

The  Principles  of  Interculture 197-213 

Tillage  machinery,  197  —  Methods  of  tillage  compared, 
206  —  Water-loss  from  fallow  soil,    207  —  Evaporation 


TABLE  OF  CONTENTS 


XV 


under  corn  crop,  208  —  The  effect  of  weeds,  208  — 
Depth  and  frequency  of  cultivation,  209  —  Growing  corn 
for  silage,  212. 

CHAPTER  XVIII 

Animal  and  Insect  Enemies       ......     214-221 

Birds,  214  —  Rodents,  214  —  Insects,   216  —  Diseases 
of  corn,  220. 


CHAPTER   XIX 

Harvesting  the  Corn  Crop 

Time  of  harvesting,  224  —  Relative  proportion  of  parts, 
226  —  Composition  of  parts,  226  —  Relative  value  of 
parts,  227  —  Time  of  harvesting  for  silage,  229  —  Meth- 
ods of  harvesting,  230 — -Comparative  cost  of  harvesting 
methods,  241  —  Shrinkage  in  curing  fodder,  243  —  Mar- 
keting, 245. 


222-248 


CHAPTER  XX 


Uses  op  Corn 


249-252 


CHAPTER   XXI 


Show  Corn  .... 

Growing  show  corn,  257. 


.    253-258 


CHAPTER  XXII 

Sweet  Corn  or  Sugar  Corn 

Varieties  and  types,  259  —  Varieties,  262  —  Seed,  263 
—  Selecting  and  curing  sweet  corn,  264  —  Growing  sweet 
corn  for  canning,  266  —  Market  sweet  corn,  270  —  Forc- 
ing sweet  corn,  273  —  Sweet  corn  in  the  home  gar- 
den, 274. 


259-275 


XVI  TABLE  OF  CONTENTS 

PART    II 

SORGHUMS 

CHAPTER  XXm 

PAGES 

The  Sorghum  Plant 279-291 

Geographical  origin,  280 —  Botanical  classification,  281 
—  The  sorghum  plant,  285  —  Physiology  of  sorghums, 
286  —  Reproduction,  287  —  Fertilization ,  287  —  Natu- 
ral crossing,  287  —  Climate  and  soils,  288  —  Sorghum 
types,  290. 


CHAPTER  XXIV 

The  Saccharine  Sorghums 293-300 

Introduction  into  the  United  States,  293 —  How  the 
crop  is  utilized,  296  —  Classification  of  sweet  sorghums, 
296. 


CHAPTER  XXV 

The  Non-saccharine  Sorghums 301-314 

Historical,  301 — Region  where  cultivated,  303  —  Sta- 
tistics of  culture,  304  — Kafir,  308— Durra,  310  — 
Shallu,  313— Kowliang,  314. 


CHAPTER  XXVI 

Cultural  Methods  for  Sorghums 315-323 

Growing  sorghums  for  grain,  315  —  Growing  sorghums 
for  forage,  321. 


TABLE  OF  CONTENTS  xvil 

CHAPTER  XXVII 

PAGES 

Utilizing  the  Sorghum  Crop 324-327 

Poultry  food,  325  —  Soiling  or  green  feed,  325  —  Pas- 
ture, 325  —  Sorghum  mixtures  for  pasture,  326— Sor- 
ghum for  silage,  326—  Sorghum  poisoning,  327. 

CHAPTER  XXVIII 

SORGHU3I    FOR    SiRUP-MAKING 328-330 

Time  of  harvesting,  328  — An  average  yield,  329. 

CHAPTER  XXIX 

Broom  Corn  ,         .        . 331-340 

Historical,  331  —  Statistics  of  culture,  331  —  Varieties, 
333— Planting,  336  — Tillage,  336  — Time  of  harvest- 
ing, 337. 


PART   I 
CORN 


CORN   CROPS 

CHAPTER  I 

PRODUCTION  AND  DISTRIBUTION  OF  INDIAN 

CORN 


The  corn  crops,  as  understood  in  this  book,  are  the  de- 
rivatives of  two  group-species:  of  Zea  Mays,  the  Indian 
corn  or  maize ;  and  of  Andropogon  Sorghum,  the  sorghum 
and  kafir  series.  The  former  is  a  plant-group  of  the  West- 
ern Hemisphere  and  the  latter  of  the  Eastern  Hemisphere. 
The  maize  products  are  used  both  for  human  and  stock 
food,  but  the  sorghum  products  are  employed  in  this 
country  mostly  for  the  feeding  of  animals. 

1.  Relative  importance  of  corn  and  other  crops  in  the 
world.  —  The  hay  and  forage  crop  is  the  most  important 
crop  of  the  world,  but  this  is  made  up  of  a  great  variety 
of  plants.  The  yield  in  millions  of  tons  of  the  world's 
most  important  plants  is  shown  in  the  following  diagram :  — 

World's  Crops  of  the   Most  Important  Food  Plants.    Average 
FOR  5  Years,  1906-1910 
_,  Millions 

<=^™P  of  Tons 


Potatoes 

156 

Corn 

113 

Wheat 

107 

Oats 

67 

Rice 

67 

Rye 

46 

Barley 

33 

nOfERIT  UBRARY 

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PRODUCTION   OF  INDIAN   CORN 


In  total  value,  the  world's  wheat  crop  probably  ranks 
first,  the  potato  crop  second,  and  the  corn  crop  third. 

2.  Corn  crop  of  the  world.  —  The  following  tables 
(I,  II)  give  the  world's  production  of  corn  for  the  past 
five  years.  The  data  is  abstracted  from  the  Year  Books 
of  the  United  States  Department  of  Agriculture  :  — 

TABLE    II 

Percentage  of  World's  Corn  Crop  produced  by  the  Con- 
tinents, AND  Principal  Corn-producing  Countries. 
For  5  Years,  1906-1910 


Continent 

1906 

1907 

1908 

1909 

1910 

Average 

North  America 
Europe        .     . 
South  America 
Africa    . 
Australia    .     . 

77.25 

15.34 

5.03 

2.15 

.23 

80.56 

14.34 

2.29 

2.49 

.32 

78.74 

14.68 

3.98 

2.36 

.24 

77.06 

15.04 

5.20 

2.42 

.28 

76.88 

16.02 

4.55 

2.25 

.29 

78.09 

15.08 

4.20 

2.35 

.28 

Total  .     . 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

Principal 

Countries 

United   States 

73.85 

75.79 

'  73.94 

71.74 

71.67 

73.39 

Austria- 

Hungary 

5.31 

5.74 

5.28 

5.92 

5.97 

5.64 

Mexico        .     . 

2.77 

4.09 

4.15 

4.77 

4.73 

4.10 

Argentina 

4.91 

2.09 

3.77 

4.98 

4.35 

4.02 

Italy       .     .     . 

2.34 

2.58 

2.65 

2.79 

2.52 

2.57 

Roumania 

3.29 

1.68 

2.18 

1.97 

2.57 

2.34 

Egypt    .     . 

1.64 

1.90 

1.80 

1.82 

1.74 

1.78 

Russia 

(European) 

1.77 

1.48 

1.69 

1.11 

1.91 

1.59 

Total  .     . 

95.88 

95.35 

95.46 

95.10 

95.46 

95.43 

The  world's  corn  crop  varies  from  about  three  and  one- 
half  bilhon  bushels  to  about  four  biUion  bushels,  or  a 
variation  of  12  per  cent.     This  rather  wide  variation  is 


4  CORN   CROPS 

due  to  the  fact  that  more  than  one-half  the  world's  corn 
crop  is  concentrated  in  one  section  of  the  United  States. 

The  comparative  production  is  brought  out  more  clearly 
in  Table  II,  based  on  percentage  production. 

From  the  tables,  it  appears  that  North  America  pro- 
duces 78  per  cent  of  the  world's  corn  crop,  Europe  pro- 
duces 15  per  cent,  leaving  only  7  per  cent  for  the  other 
continents.  The  United  States  produces  about  73  per 
cent  of  the  world's  crop,  Austria-Hungary  5.6  per  cent, 
Mexico  4.1  per  cent,  and  Argentina  4  per  cent,  the  four 
countries  combined  producing  87  per  cent  of  the  world's 
crop. 

TABLE   III 

Showing  Corn  exported  by  Countries  and  Percentage 
OF  Total  World's  Exports  for  5  Years,  1906-1910, 
Inclusive 


Country 

Average  Annual 
Export 
Bushels 

Percentage  op 
Total  Exports 

Argentina 

United  States     .... 

Roumania 

Russia  (European)       .     . 

Belgium 

Netherlands  ..... 

Bulgaria 

Servia        

Austria-Hungary    .     .     . 

Uruguay   . 

Other  Countries 

83,569,388 
62,596,444.2 
33,124,210.4 
23,255,489.2 
7,007,737.8 
6,718,712 
6,021,984.4 
3,054,136.2 
328,352.6 
210,674.2 
8,703,035 

35.66 

26.64 

14.15 

9.90 

2.93 

2.83 

2.55 

1.35 

.14 

.09 

3.75 

Total 

234,590,164.0 

100.00 

3.  International  trade  in  corn.  — ■  The  net  exports  and 
imports  indicate  those  countries  producing  a  surplus,  and 
those  countries  as  well  that  must  buy.     Table  III  shows 


PRODUCTION  OF  INDIAN   CORN  5 

that  Argentina  furnishes  about  35  per  cent  of  the  world's 
export  corn  and  the  United  States  only  26  per  cent. 
Table  IV  shows  that  Argentina  exports  55  per  cent  of  the 
crop  produced,  while  the  United  States  exports  only  2.29 
per  cent.  This  country  can  hardly  be  classed  as  a  sur- 
plus corn  country,  though  the  small  percentage  exported 
furnishes  one-fourth  of  the  world's  export  corn.  The  prin- 
cipal importing  country  is  the  United  Kingdom,  taking 
36  per  cent  of  the  world's  trade  in  corn,  and  Germany  14 
per  cent  more,  the  two  taking  one-half  the  corn  trade. 


TABLE    IV 

Showing  Percentage  of  Total  Corn  Crop  exported  by 
THE  Principal  Exporting  Countries,  5- Year  Average, 
1906-1910,  Inclusive 


Country 

Production  in 

Exportation  in 

Percentage  of 

Bushels 

Bushels 

Crop 

United  States    .     . 

2,725,367,400 

62,596,444 

2.29 

Argentina      .     .     . 

151,015,000 

83,569,388 

55.33 

European  Russia    . 

59,831,200 

23,255,489 

38.86 

Roumania     .     . 

88,163,400 

33,124,210 

37.57 

Bulgaria   .... 

22,281,800 

6,021,984 

27.02 

Europe  consumes  about  91  per  cent  of  the  world's  corn 
trade.  This  corn  is  largely  used  for  feeding  hve-stock, 
but  also  in  the  brewing  industry. 

Exportation  of  corn  from  the  United  States  is  decreasing. 
The  maximum  exportation  from  this  country  was  during 
the  5-year  period  1896-1900,  when  it  reached  an  annual 
average  of  9.4  per  cent.  The  present  decrease  in  expor- 
tation, indicates  that  home  consumption  in  the  United 
States  will  soon  equal  production.  In  fact,  in  the  past 
three  years  corn  has  been  imported  on  the  Pacific  Coast. 


CORN   CROPS 


TABLE    V 


Showing  Corn  imported  by  Countries  and  Percentage  op 
Total  World's  Imports  for  5  Years,  1906-1910,  In- 
clusive 


Country 

Av.  Annual  Import  of 
Corn  in  Bu.  for  5  Yr. 

Percentage  of 
Total  Import 

United  Kingdom     .     .     . 

Germany        

Netherland    ..... 

Belgium 

France       ...... 

Denmark 

Canada     

Italy 

Spain 

Austria-Hungary    .     .     . 

Switzerland 

Mexico 

Cuba 

Portugal 

Norway 

Egypt       

Sweden     ...... 

Russia 

British  South  Africa    .     . 
Other  Countries      .     .     . 

84,835,078 
34,189,007 
24,836,943.4 
21,984,982.6 
13,510,287.2 
12,705,123.8 
10,809,151.8 
7,737,137.8 
4,891,501 
4,170,578.2 
2,996,767.6 
2,738,086.8 
2,546,576.8 
1,169,913.4 
1,043,998 
662,416.4 
386,611 
329,755.6 
147,452.2 
3,453,661.4 

36.07 

14.53 

10.56 

9.36 

5.74 

5.45 

4.59 

3.29 

2.08 

1.77 

1.27 

1.16 

1.08 

.49 

.44 

.28 

.16 

.14 

.06 

1.46 

Total      .     .     .     .     . 

235,145,030.0 

100.00 

CORN    PRODUCTION    IN    THE    UNITED    STATES 

4.  Relative  value  of  different  crops  in  the  United 
States.  —  The  corn  crop  is  more  valuable  than  any  two 
other  crops  in  the  United  States.  The  value  of  all  wealth 
produced  on  farms,  including  that  derived  from  cereals, 
hay,  cotton,  live-stock,  forests,  and  fruit,  amounts  to 
7955  millions  of  dollars.  The  corn  crop  alone  furnishes 
about  one-fifth  of  this  annual  wealth. 


PRODUCTION   OF  INDIAN  CORN  7 

Relative  Farm  Value  of  Principal  Crops  in  the  United  States. 
Average  for  5  Years,  1906-1910 


5.  Development  of  corn  production  in    United  States 

is  shown  in  the  following  table :  — 

TABLE  VI 
Average  Production  of  Corn  at  Different  Periods 


Years 

Acres 

Bushels 
(000  omitted) 

Yield 
per  Acre 
Bushels 

Total 

Value 

(000 

omitted) 

Value    per 
Bushel 

1849    .     . 
1859    .     . 

1867-1876 
1877-1886 
1887-1896 
1897-1906 

38,688,449 
68,408,900 
74,290,879 
87,971,235 

592,071 
838,793 
1,011,535 
1,575,626 
1,800,271 
2,240,363 

26.2 
25.1 
24.0 
25.4 

Dollars 

457,000 
625,623 
633,694 
869,575 

Cents 

46.5 
40.3 
36.6 
39.0 

The  total  crop  has  about  doubled  in  40  years  and 
quadrupled  in  60  years. 

6.  Production  by  states.  —  Table  VII  gives  the  most 
important  data  summarized  on  the  production  of  corn  by 
states.  This  table  is  arranged  according  to  rank  by 
states  and  shows  that  the  eight  leading  states  produced 
about  63  per  cent  of  the  total  crop. 


CORN  CROPS 


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Wisconsin 
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Alabama 
North  Carolina 

PRODUCTION   OF  INDIAN   CORN 


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Colorado 
North  Dakota 
Connecticut 
Vermont 
Massachusetts 

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10 


COBN  CROPS 


Fig.  1.  —  Corn  production  in  the  United  States. 

Corn  per  square  mile,  census  1900:  Black  shading,  more  than  3200  bu. ;  next 
shading,  640  to  3200  bu. ;  next-to-bottom  shading,  64  to  640  bu. ;  bottom  shading, 
less  than  64  bu. 


Fig.  2.  —  Map  showing  average  yield  per  acre,  average  farm  price  per 
bushel,  and  average  shipment  out  of  county  where  grown  for  grand 
divisions  of  the  United  States. 


PRODUCTION   OF  INDIAN   CORN 


11 


7.  Production  by  sections,  and  market  movement. —  The 

following  summary,  together  with  Fig.  2,  gives  a  definite 
idea  of  the  relative  production  in  different  sections  of  the 
country,  and  also  the  comparative  market  movement. 
The  available  data  is  corn  shipped  out  of  the  county  where 
grown,  and  does  not  always  mean  that  the  corn  leaves 
the  state,  but  indicates  the  surplus  corn  in  the  hands  of 
growers.  Most  of  the  lesser  corn  states  consume  more 
corn  than  they  raise,  while  in  the  principal  corn-belt,  most 
of  the  corn  put  on  the  market  leaves  the  state,  and  is 
utilized  in  manufacturing  corn  products  or  shipped  to  other 
regions :  — 

TABLE  VIII 

Table  showing  Percentage  of  Entire  Corn  Crop  pro- 
duced BY  Each  Grand  Division  of  the  United  States 
AND  the  Market  Movement.  5-Year  Average,  1906- 
1910,  Inclusive 


Grand 
Division 

Total  Pro- 
duction 

Per  Cent 
OF  Total 
Produc- 
tion 

SHIPPED 

Amount 

SHIPPED 

Per  Cent 

of  Total 

shipped 

Per  Cent 

Total 
Crop  op 
Each  G. 

Div. 
shipped 

North  Atlantic 
South  Atlantic 
North   Central 

East     Miss. 

River       .     . 
North  Central 

West    Miss. 

River       ,     , 
South    Central 
Far  West    .     . 

90,543,473 
223,216,236 

777,297,616 

1,027,233,955 

597,806,892 

9,329,243 

3.32 
8.19 

28.53 

37.69 

21.93 

.34 

5,817,676 
20,134,990 

255,966,226 

249,041,882 

77,974,324 

810,453 

.96 
3.30 

41.98 

40.84 

12.78 

.14 

6.42 
9.02 

32.93 

24.24 
13.04 

8.68 

Total   .     . 

2,725,427,415 

100. 

609,745,551 

100. 

SECTION  I 
THE   CORN   PLANT 


CHAPTER  II 
ORIGIN  AND  CLASSIFICATION 

In  common  with  all  living  organisms,  corn  has  been  de- 
veloped through  a  long  and  slow  evolutionary  process. 
We  can  only  guess  at  the  probable  place,  origin,  and  course 
of  evolution  by  a  study  of  botanically  related  forms,  and 
especially  by  a  consideration  of  the  embryonic  develop- 
ment of  the  corn  plant  itself.  How  much  of  the  evo- 
lutionary change  was  wrought  by  natural  selection,  and 
how  much  is  the  result  of  artificial  selection,  we  can  never 
know.  It  is  probable  that  corn  reached  a  stage  of  eco- 
nomic value  before  attracting  the  attention  or  care  of 
man.  Since  then,  no  doubt  most  of  the  further  changes 
are  the  result  of  natural  variation  and  artificial  selection. 

8.  Geographical  origin.  —  Numbers  of  investigators 
have  made  careful  studies  regarding  the  probable  region 
in  which  Indian  corn  originated.  In  the  early  part  of 
the  nineteenth  century,  there  was  some  controversy  as  to 
whether  this  plant  was  of  American  origin,  the  question 
being  based  on  the  contention  of  some  persons  that  maize 
had  been  cultivated  in  Europe  previous  to  the  discovery 
of  America.  Careful  investigation  has  not  disclosed 
proof  of  this  supposition,  and  it  is  not  likely  that  a  plant 
of  such  easy  culture  and  obvious  value  could  have  existed 
in  Europe  without  being  known.  According  to  Harsh- 
berger,  it  seems  most  probable  that  the  cultivation  of 
maize  originated  in  the  high  plateau  region  of  central  or 


16  CORN   CROPS 

southern  Mexico  at  an  elevation  of  about  4500  feet. 
In  this  region,  plants  of  Zea  canina  are  found  growing  wild  ; 
it  is  also  the  native  habitat  of  teosinte  and  gama  grass, 
two  plants  closely  related  botanically  to  maize.  Harsh- 
berger  concludes  that  maize  probably  came  into  cultiva- 
tion in  this  region  about  the  beginning  of  the  Christian 
Era  and  spread  rapidly  both  north  and  south,  reaching 
the  Rio  Grande  about  700  a.d.,  and  the  coast  of  Maine 
not  later  than  the  year  1000. 

When  Columbus  visited  America  in  1492,  maize  was  in 
common  cultivation.  It  was  at  once  introduced  into 
other  parts  of  the  world,  reaching  Europe,  Africa,  China, 
and  Asia  Minor  early  in  the  sixteenth  century.  Its  early 
culture  in  the  Eastern  Hemisphere  seems  to  have  been 
confined  mostly  to  the  countries  bordering  on  the  Mediter- 
ranean Sea. 

Maize  acquired  many  names  in  Europe,  such  as  Spanish 
corn,  Roman  corn,  Guinea  corn,  Turkish  wheat,  Egyptian 
corn ;  these  names  probably  indicate  the  places  where  its 
culture  first  became  extensive. 

9.  Biological  origin.  —  The  Graminese,  or  grass  family, 
includes  most  of  our  common  cereals,  as  maize,  oats, 
wheat,  and  rye.  A  distinguishing  feature  of  the  tribe 
Maydece,  to  which  maize  belongs,  is  the  separation  of  its 
staminate  flowers  (pollen-bearing)  from  its  pistillate 
flowers  (seed-bearing).  Two  grasses  related  to  maize 
and  of  common  occurrence  in  Mexico  —  the  region  in 
which  corn  is  supposed  to  have  originated  —  are  gama 
grass  {Tripsacu7n  dactyloides)  and  teosinte  {Euchlcena 
Mexicana) . 

Gama  grass  is  distributed  also  over  the  southern  half 
of  the  United  States  and  usually  is  found  on  low,  rich 
soil.     At  a  distance  a  patch  of  this  grass  looks  very  much 


Fig.  3.  —  The  relationship  between  gama,  teosinte,  and  corn. 
1.  Gama  grass  {Tripsacum  dactyloides) .  2.  Teosinte  (Euchlcena  Mexicana). 
3.  Corn  {Zea  mays).  4.  Floral  parts  of  gama  grass:  a,  tassel;  b,  spike  of  tassel, 
bearing  staminate  flowers  on  upper  part,  and  pistillate  flowers  on  lower  part; 
c,  staminate  flower ;  d,  pistillate  flower.  5.  Floral  parts  of  teosinte.  6.  Floral  parts, 
of  corn. 

c  17 


18  CORN  CROPS 

like  maize.  While  it  grows  to  a  height  of  five  to  ten  feet, 
the  stem  is  slender  and  the  leaf  about  half,  the  width  of 
the  maize  leaf.  The  plant  bears  a  tassel-like  structure 
at  the  top  and  on  the  lateral  branches,  closely  resem- 
bling the  maize  tassel,  except  that  the  seeds  are  borne 
on  the  lower  part  of  each  tassel  and  the  pollen  on  the 
upper  part. 

Teosinte,  which  is  sometimes  cultivated  but  does  not 
mature  north  of  Mexico,  is  more  like  maize  than  is  gama 
grass,  the  plant  being  larger  and  the  terminal  tassel  bear- 
ing pollen  only.  The  lateral  branches  of  the  plant  are  so 
shortened  that  the  terminal  tassel-like  structure  is  borne 
in  a  leaf  axil,  surrounded  by  a  kind  of  husk  as  is  an  ear 
of  maize,  and  bears  only  pistillate  flowers,  or  seed.  It  is 
only  a  step  in  the  production  of  an  ear  of  maize,  from 
teosinte,  by  a  development  of  the  central  spike  of  the 
lateral  tassel  into  an  ear. 

It  is  probable  that  the  early  progenitor  of  maize  was  a 
grass-like  plant  having  a  tassel  at  the  top  and  tassel-like 
structures  on  long,  lateral  branches,  all  tassels  bearing 
perfect  flowers.  As  evolution  progressed,  the  terminal 
tassel  came  to  produce  only  pollen,  and  the  side  branches 
only  ovules,  or  seeds.  Evolution  often  results  in  a  greater 
"  division  of  labor,"  as  in  this  case.  At  the  same  time,  the 
lateral  branches  were  shortened  or  telescoped  into  the 
leaf  sheaths,  these  sheaths  forming  a  covering,  or  husk, 
for  the  ear.  Also  it  is  probable  that  in  this  evolution  the 
central  spike  of  the  tassel  developed  into  an  ear. 

The  close  relationship  of  maize  and  teosinte  is  proved 
by  the  crosses  that  have  been  made  between  the  two.  In 
the  third  or  fourth  generation  after  crossing,  a  pecuhar 
type  of  corn  is  secured,  identical  with  a  type  of  maize  that 
has  been  found  growing  wild  in  Mexico  {Zea  canina),  and 


ORIGIN  AND   CLASSIFICATION 


19 


20 


COBN   CROPS 


is  supposed  by  some  persons  to  be  the  true  wild  maize 
and  the  progenitor  of  our  cutivated  maize. 

Watson  and  Bailey  both  studied  this  wild  maize  and 
regarded  it  as  a  distinct  species ;  however,  since  it  has 
been  produced  by  hybridizing  teosinte  and  maize,  this 
probably  accounts  for  its  origin. 

CLASSIFICATION    OF    MAIZE    IN    (; ROUPS 

Order  —  Graminece 
Tribe  —  Maydece 
Genus  —  Zea 
Species  —  Mays 

10.  Maize  may  be  classified  into  the  following  groups, 
or  "  agricultural  species  "  (after  Sturtevant)  :  — 

1.  Zea  Mays  canina  (Watson),  Maiz  de  Coyote.  Said  to 
grow  wild  in  Mexico,  but  the  same  type  has  been  produced 
artificially  by  crossing  teosinte  and  common  maize. 
Characterized  by  a  branching  plant  and  by  the  production 

of  numerous  small  ears  in 
the  leaf  axils  of  lateral 
branches ;  ears  sometimes 
clustered;  4  to  8  rows  on 
an  ear,  and  ear  2  to  4 
inches  in  length. 

2.  Zea  Mays  tunicata,  the 
pod  corns,  Bui.  Torrey  Bot. 
Club,  1904. 

Each  kernel  inclosed  in 
a  pod  or  husk  and  the  ear 
inclosed  in  husks ;  not  com- 
mon. All  forms  of  kernel,  as  sweet,  dent,  flint,  and 
others,  are  found  in  pod  corn.  Occasionally  a  few  podded 
kernels  will  occur  on  ears  of  ordinary  corn.     It  has  been 


Fig.  5.  —  Pod  corn. 


ORIGIN  AND   CLASSIFICATION 


21 


Fig.  6.  —  Pop  corn. 


supposed  by  some  persons  that  pod  corn  represented 
a  primitive  or  early  type  of  corn,  but  there  is  no  good 
evidence  for  this  surmise. 

3.  Zea  Mays  everta,  the  pop  corns. 
Characterized  by  the  excessive  proportion  of  corneous 
endosperm  and  the  small  size  of  the  kernels  and  ear.     The 
popping  quality  is  due  to  the  explosion 
of  contained  moisture  on  the  applica- 
tion of  heat,  and  the  best  varieties 
for    popping    are    usually    corneous 
throughout.     Two  forms  of  seed  are 
common,  one  of  which  is  pointed  at 
the  top  (rice  pop  corn) ,  and  the  other 
form    is  rounded   (pearl   pop   corn), 
much  as  a  small   flint.      All   maize 
colors  are  found,  as  red,  yellow,  white, 
and  blue.     The  ears  are  small  but  vary  in  length  from 
2  inches  in  Tom  Thumb  to  5  inches  for  rice  and  7  inches 

for  some  of  the  large  pearl 
types.  Rows  vary  from 
8  to  16. 

4.  Zea  Mays  indurata,  the 
flint  corns. 

Characterized  by  white 
starchy  endosperm,  inclosed 
by  flinty  endosperm.  Ker- 
nels oval  in  form ;  in  some 
varieties  the  corneous  part  is  very  thin  at  the  top  and  a 
slight  indentation  appears.  There  are  types  of  flint 
maize  closely  resembling  pop  corn  on  the  one  hand  and 
approaching  dent  on  the  other,  thus  forming  a  series 
between  the  pop  and  dent  corns.  Flint  maize  has  all  the 
common  maize  colors.     It  varies  in  length  of  ear  from  8  to 


Fig    7. 


Flint  corn. 


22 


CORN  CROPS 


Fig.  8. — Dent  corn. 


various 


in 


14  inches,  and  has  6  to  12  rows.     The  maize  most  com- 
monly   cultivated    by  the    early    colonists    and    North 
American  Indians  is  extensively  cultivated  at  present  in 
^^^^^^^^^_^^^——————,      regions  where  the  large  dents 

^H^^^^^^^^^^H      do 

^HH^H^pHjI^H  5.  Zea  Mays  indentata,   the 

^f^  J  ^      dent  corns. 

K:  *  I  Characterized  by  horny  endo- 

Bi  I  fl      sperm  at  the  sides,  with  starchy 

^K  ■  fl      endosperm    extending    to    the 

^^^^'^^^L  ^^B  summit.  By  shrinkage  of  the 
^^^h^^^^l^^H  starchy  matter  in  drying,  the 
HHm^^l^^^^l      summit  of  the  kernel  is  drawn 

in  and  indented  in 
forms.  The  plant  varies 
height  from  5  to  18  feet ;  the  ear  varies  in  length  from 
6  to  12  inches  and  has  8  to  24  rows.  The  most  com- 
monly cultivated  type  in  the  United  States. 

6.  Zea  Mays  amylacea,  the  soft  corns. 
Characterized  by  entire  absence  of  corneous  endosperm. 

All  soft.  No  indentations,  the  kernel  being  shaped  hke 
that  of  flint  corn.  Ears 
mostly  8  to  12-rowed,  8  to 
10  inches  in  length.  The 
usual  colors  occur.  Culti- 
vated to  some  extent  in 
Southwestern  States,  Mexico, 
and  South  America. 

7.  Zea  Mays  saccharata,  the 
sweet  corns. 

Characterized  by  the  translucent,  horny  appearance  and 
more  or  less  wrinkled  condition  of  the  kernel.  Shrinking 
probably  due  to  the  conversion  of  starch  into  glucose. 


Soft  corn. 


OBIGIN  AND   CLASSIFICATION 


23 


According  to  East,  sweet  corns  are  either  dent  or  flint 
corns  that  have  failed  to  convert  their  sugars  into  starch. 
Usual  variations  in  color,  size, 
and  time  of  maturity. 

Zea  Mays  japonica.  The 
leaves  of  this  species  are 
striped  green  and  white ;  the 
grain  resembles  a  pop  or  small 
flint  type.  Cultivated  as  an 
ornamental. 

Zea  Mays  hirta.    Character- 
ized by  an  unusual  amount  of 
hairs   on   leaves    and    sheath, 
sufficient  to  be  distinctly  noticeable.    Flint,  pop,  and  dent 
types.     Found  mostly  in  South  America. 


Fig.  10.  —  Sweet  corn. 


Fig.  11.  —  The  six  principal  types  of  corn.     From  left  to  right,  pod  corn, 
pop  corn,  flint  corn,  dent  corn,  soft  corn,  and  sweet  corn. 


24  CORN   CROPS 

Zea  Mays  curagiia.  Characterized  by  a  serrate  leaf 
edge.     Probably  a  flint  type. 

Chinese  maize.  A  small-eared  type  resembling  pearl 
pop  corn,  but  characterized  by  a  softer,  opaque  endo- 
sperm. Not  starchy.  A  tendency  for  the  upper  leaves 
to  be  on  one  side  of  the  plant.  (See  Bur.  Plant  Indus., 
Bui.  161.) 

Hermaphrodite  forms  (perfect  flowers).  A  hermaphro- 
dite form  has  been  described  several  times.  Each  pistil- 
late flower  bears  3  stamens.  The  plant  is  usually  short- 
jointed,  with  very  broad  leaves.  (See  Exp.  Sta.  Rec, 
Vol.  18,  p.  732.     Pop.  Sci.  Mo.     Jan.  1906.;   Oct.  1911.) 

References  on  early  history  :  — 

Darwin,  Chas.  (1874.)  Animals  and  Plants  under  Domestica- 
tion, p.  338. 

De  Candolle,  a.      (1882.)     Origin  of  Cultivated  Plants,  p.  387. 

Sturtevant,  E.  L.  (1899.)  U.  S.  Dept.  Agr.,  Office  of  Exp.  Sta., 
Bui.  57. 

Harshberger,  John  W.  (1893.)  Maize:*  A  Botanical  and 
Economic  Study.     Bot.  Lab.  Univ.  Penn.,  Vol.  I,  No.  2. 

Collins,  G.  N.  (1909.)  U.  S.  Dept.  Agr.,  Bur.  Plant  Indus., 
Bui.  161. 

References  on  biological  origin  of  maize :  — 
Hackel.     (1890.)     True  Grasses.     Translated  by  Scribner  and 

Southworth,  pp.  36-43. 
Grasses  of  Iowa,  Bui.  Iowa  Geol.  Survey,  1903. 
Harshberger,    J.    W.     Maize :     A    Botanical    and    Economic 

Study.     Bot.  Lab.  Univ.  Penn.,  Vol.  I,  No.  2,  p.  94. 
Montgomery,  E.  G.     (1906.)     What  is  an  Ear  of  Corn?     Pop. 

Sci.  Mo.,  Jan.  1906.     Perfect  Flowers  in  Maize.    Same,  Oct. 

1911. 

References  on  Zea  canina :  — 
Watson.     Proc.  Amer.  Acad.  Arts  and  Sci.,  26 :  160.     Grasses  of 

Iowa.     Bui.  Iowa  Geol.  Survey,  1903:  11-19. 
Bailey,  L.  H.     (1892.)     Cornell  Univ.  Agr.  Exp.  Sta.,  Bui.  49. 


pHOnRTY  UBRARY 


ORIGIN  AND   CLASSIFICATION  25 

References  to  crosses  of  maize  and  teosinte  :  — - 
Harshberger,  J.  W.    Crosses  of  Teosinte  and  Maize.     Garden 

and  Forest,  IX  :  522. 
U.  S.  Dept.  Agr.  Year  Book,  1909 :  312. 

References  on  classification  of  maize  :  — 
BoNAFAUs.     Mais,  folio.     Paris,  1836  (folio). 
Index  Kewensis. 

Sturtevant,  E.  L.     (1899.)     Varieties  of  Corn.     Bui.  57,  Office 
of  Exp.  Sta.,  U.  S.  Dept.  Agr. 


CHAPTER  III 
DESCRIPTION  OF  THE  CORN  PLANT 

Under  the  head  ''Biological  Origin"  (page  15)  it  is 
seen  that  corn,  through  a  process  of  evolution,  probably 
came  from  some  branched,  grass-like  plant  resembling 
teosinte.  In  Fig.  13  is  shown  a  drawing  of  a  corn  plant, 
with  leaves  removed,  illustrating  the  grass-like  character. 

The  main  stem  is  divided  by  nodes.  Below  the  ground, 
the  nodes  are  very  close  together  and  give  rise  to  roots ; 
at  the  surface  they  give  rise  to  branches  or  tillers  and 
also  roots,  and  above  ground  to  leaves  and  ears. 

The  branches  or  tillers  correspond  in  detail  to  the  main 
stem,  having  in  all  cases  as  many  nodes  and  leaves  as  the 
main  stem  above  the  point  of  attachment.  The  ear  is 
only  a  modified  branch,  as  the  ear  stem  has  exactly  the 
same  number  of  nodes  as  the  main  stem  above,  and  the  ear 
corresponds  in  many  details  to  the  tassel. 

11.  The  root.  —  When  a  kernel  of  maize  germinates  there 
is  produced,  first,  a  root  from  the  tip  end  of  the  seed.  A 
few  hours  later  the  stem  will  appear  at  the  upper  end  of 
the  germ  chit.  At  nearly  the  same  time  two  roots  will  be 
sprouting  from  about  the  median  point  between  root  and 
stem.  These  are  the  ''  temporary"  roots  and  maintain  the 
plant  for  only  a  short  time.  When  the  corn  plant  is 
about  six  to  ten  days  old,  whorls  of  permanent  roots  begin 
to  develop  at  a  point  about  one  inch  below  the  ground 
surface.     The  seed  may  be  planted  1  to  5  inches  deep, 

26 


DESCRIPTION  OF  THE  CORN   PLANT 


27 


Fig.  12. — Corn  roots.  1.  Ordinary  distribution  of  roots  when  corn  is 
planted  in  rows  three  feet  six  inches  apart  in  a  deep  loam  soil.  Figures 
in  margin  indicate  feet.  In  a  hardpan  soil  roots  do  not  penetrate  so 
deep.  2.  Single  lateral  root.  3.  Small  branch  root  showing  root- 
hairs.  4.  Root  and  root-hairs  enlarged.  5.  Cross-section  of  4  at 
point  a.    7.  Root-hair  in  contact  with  soil  grains. 


28  CORN  CROPS 

but  the  permanent  roots  develop  at  about  the  same  dis- 
tance below  the  surface. 

12.  The  spread  of  the  roots.  —  Root  studies  on  maize 
at  the  Wisconsin,  Minnesota,  Colorado,  New  York,  and 
North  Dakota  experiment  stations  indicate  that  the 
permanent  roots  first  spread  laterally  for  about  nine  to 
twelve  days,  when  they  will  have  reached  a  distance  16 
to  18  inches  from  the  plant  and  will  be  confined  mostly 
to  a  zone  between  3  and  6  inches  below  the  surface.  From 
this  time  on,  the  root  system  rapidly  extends  downward 
as  well  as  laterally,  at  eighteen  days  reaching  a  depth  of 
about  12  inches  and  at  twenty-seven  days  a  depth  of  18 
inches,  with  a  lateral  extension  of  24  inches.  By  the  time 
the  maize  plants  are  two  months  old,  when  they  are  5  to 
6  feet  high  and  coming  in  tassel,  the  lateral  spread  of  roots 
has  a  radius  of  about  4  feet  and  penetrates  the  soil  to  a 
depth  of  3  to  4  feet.  The  number  of  roots  continues  to 
increase  until  the  plant  is  mature,  when  they  fully  occupy 
the  upper  3  to  4  feet  of  soil. 

The  depth  to  which  roots  may  penetrate  is  somewhat 
dependent  on  the  character  of  the  soil,  as  is  shown  by  the 
Colorado  station.  In  a  black  adobe  soil,  the  roots  were 
limited  mostly  to  the  upper  12  inches,  while  on  another 
heavy  soil  containing  much  clay  they  penetrated  only  24 
inches. 

13.  Distance  from  surface.  —  At  a  distance  of  6  inches 
from  the  plant  the  upper  roots  are  usually  about  3  inches 
below  the  surface,  sloping  gently  to  4  or  5  inches  deep  at  a 
distance  of  2  feet  from  the  plant.  However,  when  there  is 
abundance  of  moisture  in  the  surface,  feeders  may  come 
within  2  inches  or  less.  Distance  from  the  surface  seems 
to  be  controlled  by  the  presence  of  sufficient  moisture,  and 
also  by  the  degree  of  shading,  since  roots  are  very  sensitive 


DESCRIPTION   OF  THE   CORN  PLANT  29 

to  light.  Late  in  the  season,  when  the  soil  is  well  shaded, 
roots  will  be  found  very  near  the  surface ;  but  ordinarily, 
during  the  growing  season,  they  are  3  to  4  inches  below. 
The  method  of  planting  may  also  exercise  some  influence 
on  the  depth  of  upper  roots.  At  the  Kansas  station,^ 
where  the  root  systems  of  "  listed  "  corn  were  compared 
with  those  of  surface-planted,  the  upper  roots  of  the 
former  were  found  to  average  about  1  inch  deeper  during 
the  cultivating  season,  especially  near  the  plant,  thus 
permitting  deeper  cultivation. 

14.  Types  of  roots.  —  Maize  roots  may  be  classed  as 
primary  roots,  brace  roots,  lateral  roots,  and  hair  roots. 
The  main  roots  are  those  having  their  origin  at  the  base 
of  the  stem;  they  are  twenty  to  thirty  in  number  and 
4  to  6  feet  in  length.  The  lateral  roots  are  numerous  small 
roots  thrown  off  from  these,  and  they  again  may  produce 
other  laterals.  Their  number  is  very  large  and  may  aver- 
age several  hundred  to  each  main  root;  in  length  they 
vary  from  less  than  1  inch  to  1  or  2  feet.  The  root-hairs 
are  microscopic  in  size,  single-celled,  and  infinite  in  number. 
They  are  borne  on  the  main  roots  in  their  earlier  growth, 
and  on  all  the  laterals.  Root-hairs  are  short-lived  and 
limited  to  the  newer  root  growth,  or  rather  to  a  zone  near 
the  growing  point  of  the  roots.  They  are  absorbent  or- 
gans, and  do  not  grow  to  be  roots. 

15.  The  proportion  of  root.  —  The  total  weight  of  the 
root  in  a  corn  plant  has  been  found  to  be  about  12  to  15 
per  cent  of  the  weight  of  the  total  plant,  including  the 
ear. 2  The  total  length  of  roots  laid  end  to  end,  of  a  single 
plant  of  small  grain,  as  wheat  or  oats,  has  been  estimated 
at  1600  feet ;  but  in  a  corn  plant  it  would  be  greater. 

1  Kan.  Agr.  Exp.  Sta.,  Bui.  137:  203. 

2  KiESSELBACH.     Nebr.  Agr.  Exp.  Sta.,  Rpt.  1910  :  131. 


30  CORN  CROPS 

16.  The  amount  of  root.  —  The  amount  of  root  devel- 
oped is  more  or  less  in  response  to  the  needs  of  the  plant. 
When  moisture  is  abundant  or  excessive,  the  plant  will  not 
develop  so  much  root  as  when  the  moisture  content  is 
normal  or  below  normal.  Also  in  very  dry  soil,  with  a 
moisture  content  below  the  wilting  point  of  plants  (about 
12  per  cent  in  loam  soils),  the  growth  of  roots  is  limited, 
as  is  also  the  case  when  the  soil  is  very  hard. 

17.  Functions  of  the  root.  —  The  root  functions  may  be 
stated  as  :  (1)  the  absorption  of  water  and  of  salts  in  solu- 
tion; (2)  the  excretion  of  organic  substances,  especially 
carbon  dioxid,  and  possibly  free  organic  acid,  also  mineral 
salts  and  the  salts  of  organic  acids ;  (3)  the  solvent  effect 
of  the  excretions  on  soil  particles. 

The  absorption  of  water  and  solutions,  as  well  as  the 
exudations,  take  place  largely  through  the  root-hairs. 
These  root-hairs  are  constantly  produced  from  the  epider- 
mal cells  near  the  growing  root  tip.  They  are  forced  into 
close  contact  with  the  soil  grains ;  in  fact,  the  soil  grains 
are  more  or  less  embedded  in  the  root-hair  tissues.  Each 
soil  grain  in  a  moist  soil  is  surrounded  by  a  film  of  water 
containing  more  or  less  mineral  matter  dissolved  from  the 
soil.  This  soil  water  is  absorbed  by  the  root-hair,  and  it 
seems  probable  that  exudations  from  the  root-hair  also  aid 
in  freeing  less  soluble  minerals  in  the  soil  grains.  The 
process  of  absorption  is  by  means  of  osmosis.^ 

1  Osmosis.  —  When  two  solutions  of  different  density  are  separated  by 
a  porous  membrane,  there  will  be  first  a  movement  of  the  weaker  solu- 
tion through  the  membrane  into  the  stronger,  and  later  a  return  move- 
ment, the  process  continuing  until  the  two  solutions  have  the  same  den- 
sity. The  contents  of  a  root-hair  being  denser  than  the  soil  solution 
surrounding  it,  there  is  a  constant  movement  of  the  soil  solution  into  the 
root-hair.  By  some  means  the  exosmosis,  which  would  take  place  in  the 
case  of  an  ordinary  membrane  (movement  of  the  cell  solution  outward), 
seems  to   be   restrained   in   the  root-hair,  probably  by  some  functional 


DESCRIPTION   OF  THE  CORN  PLANT  31 

18.  The  stem.  —  The  stem  of  maize  differs  from  that  of 
other  cereals  in  the  fact  that  it  is  sohd  —  filled  with  pith  — 
while  others  are  hollow.  The  maize  stem  may  vary  in 
height  from  2  feet,  in  the  case  of  dwarf  pop  corn,  to  18  or 
20  feet  in  some  of  the  tall  southern  varieties. 

The  nodes  not  only  serve  to  strengthen  the  stem,  but 
are  also  the  points  of  origin  for  all  its  lateral  outgrowths, 
as  roots,  branches  (tillers),  leaves,  and  ears. 

The  stem  usually  extends  not  more  than  three  to  five 
inches  below  the  ground  surface.  This  part  is  divided 
into  about  six  to  ten  short  nodes,  each  bearing  a  whorl 
of  roots.  Above  the  soil  surface  each  node  bears  a  leaf 
and  in  addition  either  a  branch  or  an  embryonic  ear.  The 
early  northern  varieties  of  maize,  with  a  height  of  about 
6  feet,  usually  have  about  eight  to  ten  nodes  above  the 
soil,  while  the  tall  southern  varieties  may  have  eighteen 
to  twenty.  A  typical  plant  in  Illinois  or  Indiana  will 
have  about  fourteen  nodes,  with  one  or  two  branches  from 
the  surface  nodes  and  an  embryonic  ear  at  each  node ; 
usually,  however,  only  the  ear  at  about  the  eighth  node 
develops,  the  others  remaining  dormant. 

In  Fig.  13  is  shown  a  stem  from  a  plant  about  10  inches 
high.  The  full  number  of  nodes,  and  also  of  leaves,  is 
formed.  Growth  of  the  stem  from  this  point  on  will  be  by 
a  lengthening  of  the  internodes,  but  there  will  be  no  in- 
crease in  number  of  nodes.  This  is  called  internodal 
growth,  in  distinction  from  the  apical,  or  terminal,  growth 
of  many  other  plants  —  as  peas  and  beans,  where  new 
growth  is  constantly  taking  place  at  the  apex. 

The  outer  part  of  the  stem  is  a  thin  shell  of  hard  tissue, 

activity  of  the  cell.  The  result  is  a  much  greater  movement  into  the 
root-hair  than  exudation  out  of  it.  The  soil  solution  passes  from  the 
root-hair  into  the  root  and  is  finally  transmitted  to  the  stem  and  leaves. 


32 


CORN   CROPS 


the  function  of  which  is  to  give  strength  and  rigidity.     A 
cross-section  of  the  stem  will  show,  in  addition  to  the  pith, 


Fig.  13.  —  Development  of  the  corn  stem. 
1.  Plant  about  10  inches  high.  2.  Section  of 
1,  at  base,  showing  that  all  nodes,  leaves,  and 
tassel  are  more  or  less  developed  at  this  stage ; 
growth  is  internodal.  3.  Full-grown  stem 
with  leaves  removed.  4.  Cross-section  of 
stem. 


a  large  number  of  fibrous  strands, 
known  technically  as  fibro-vascular  bun- 
dles. It  is  through  these  bundles  that 
the  water  taken  in  by  the  roots  passes 
up  the  stem  and  is  distributed  through- 
out the  plant ;  and  again,  when  the 
leaves  have  elaborated  plant-food  from 
the  material  taken  up  from'  the  soil  and 
out  of  the  air,  this  plant-food  is  carried 
down  these  same  fibro-vascular  bundles  and  distributed 
to  those  parts  where  it  is  needed,  as  the  growing  ear  or 
the  roots. 


DESCRIPTION   OF  THE  CORN  PLANT  33 

19.  Tillers.  —  If  a  young  corn  plant  about  8  inches  high 
is  carefully  dissected,  two  or  more  small  buds  will  be  noted 
in  the  axils  of  the  first  leaves.  If  conditions  are  favorable, 
one  or  more  of  these  buds  will  develop  into  a  branch  of 
the  plant,  or  a  "  tiller."  If  conditions  are  unfavorable, 
as  in  poor  soil,  or  when  the  plants  are  close,  the  buds  may 
remain  suppressed  and  never  grow.  On  a  cold  clay  or  wet 
soil  very  few  of  the  tillers  develop ;  while  on  a  warm,  sandy 
soil,  especially  if  fertile,  every  plant  may  develop  one  to 
three  or  four  tillers.  A  good  example  of  this  is  the  very 
abundant  tillering  common  in  cornfields  in  the  light  but 
fertile  soils  on  the  west  edge  of  the  corn-belt  (central 
Nebraska)  ;  while  the  same  varieties  on  the  heavier  clay 
soils  of  Ohio  or  New  York  will  rarely  develop  tillers. 
Every  corn  plant  has  several  latent  buds,  which  may 
develop  if  conditions  are  favorable,  but  which  otherwise 
may  remain  dormant.  The  tiller  may  develop  its  own 
root  system  and  ears,  and  may  function  in  all  respects  as  a 
normal  plant.  A  tendency  to  tiller,  however,  is  somewhat 
hereditary,  as  certain  small  varieties  of  flint  and  sweet 
corn  normally  produce  well-developed  ear-bearing  tillers, 
while  some  of  the  large  dent  varieties  seldom  tiller. 

20.  Leaves.  — ■  If  a  small  corn  plant  a  few  days  old  be 
taken  and  a  cross-section  made  just  above  the  first  node, 
the  full  number  of  leaves  may  be  identified,  wrapped  into 
a  kind  of  stem  (Fig.  13).  As  the  stem  elongates  the 
leaves  are  gradually  exposed,  but  the  leaf  growth  takes 
place  mostly  while  the  leaves  are  yet  enfolded.  There  is 
very  little  increase  in  size  after  the  leaf  is  fully  exposed. 

The  structure  of  a  leaf  is  more  complicated  than  appears 
from  a  casual  examination,  because  of  its  many  functions. 
The  functions  are  principally :  (1)  to  provide  for  the  free 
circulation  of  solutions  and  air  throughout  the  leaf ;    (2)  to 


34 


CORN  CROPS 


give  off  constantly  large  quantities  of  excessive  water 
taken  up  by  the  roots ;  (3)  to  elaborate  plant-food  from 
the  minerals  and  water  taken  out  of  the  soil,  combined 
with  carbon  and  oxygen  taken  from  the  air ;  (4)  to  ab- 
sorb energy  from  the  sun  which  is  necessary  in  order  that 


Midrtb 


Fig.  14.  —  Leaf  structure.  The  movement  of  water  and  solutions  takes 
place  through  the  fibro-vascular  bundles.  The  mesophyll  tissue  fur- 
nishes the  means  for  elaborating  plant-food  from  raw  material.  Inter- 
change of  air  and  gases  takes  place  through  the  stomata.  The  bulli- 
form  cells  are  similar  to  mesophyll  cells,  but  contain  a  large  percentage 
of  water.    Shrinkage  of  these  cells  causes  the  leaf  to  roll  in  dry  weather. 

these  activities  may  proceed.  Each  of  the  above  functions 
of  the  leaf  requires  specialized  tissues  which  are  briefly  de- 
scribed as  follows  (21,  22)  :  — 

21.  The  vascular  system.  —  If  a  maize  leaf  is  examined, 
there  will  be  found  running  lengthwise  a  large  number  of 


DESCRIPTION   OF  THE  CORN  PLANT 


35 


parallel  veins.  On  examining  a  cross-section  of  the  leaf 
under  the  microscope,  each  vein  will  be  seen  to  contain  a 
fibrous  bundle  •  of  various  kinds  of  tissues,  known  as  a 
fibro-vascular  bundle.  In  Fig.  14  are  shown  some  of  these 
large,  thick-walled  cells,  resembling  somewhat  the  veins  of 
an  animal ;  and  it  is  by  means  of  these  that  solutions  are 
circulated  through  the  leaf.  These  fibrous  bundles  ex- 
tend into  the  stem  and  the  roots,  making  a  direct  passage 
for  the  transfer  of  soil  solutions  taken  up  by  the  roots 
through  the  stem  and  out  into  the  leaves. 

22.  Air  passages.  —  Throughout  the  leaf  tissues  are 
systems  of  air  passages.  These  are  connected  with  small 
openings  of  the  leaf  surface,  or  stomata.  Fresh  air  is  con- 
stantly coming  into  the  leaf  through  these  stomata,  car- 
rying carbon  dioxid  and  oxygen,  both  of  which  are  utilized 
by  the  plant  in  connection  with  the  minerals  taken  up  from 
the  soil  and  elaborated  into  plant-food. 

23.  Loss  of  water.  —  As  the  air  passes  out  of  a  leaf  it 
constantly  carries  out  the  water  that  has  been  taken  up 
from  the  earth.  The  outer  covering,  or  epidermis,  of  the 
leaf  is  impervious  to  water  or  air,  but  there  are  stomata 
at  regular  intervals.     The  number  of  these  is  very  great, 


Kind  of  Leaf 

Number  of  Stomata  in 
One  Square  Inch 

Upper  Side 

Under  Side 

Indian  corn  {Zea,  Mays) 

Sunflower  (Helianthus  annuus) 
Red  clover  (Trifolium  pratense) 

Hop  (Humulus  hupulus) 

Apple  {Pyrus  Mains) 

Pea  {Pisum  sativum) 

60,630 

112,875 

113,515 

0 

0 

65,145 

101,910 
209,625 
216,075 
165,120 
156,670 
139,320 

36  CORN  CROPS 

usually  being  most  numerous  on  the  under  side.  The 
above  table  gives  the  number  estimated  for  several 
kinds  of  leaves.^ 

The  stomata  also  close  more  or  less  when  the  leaves  begin 
to  wilt,  thus  preventing  to  some  extent  the  loss  of  moisture. 

24.  Chlorophyll-bearing  cells.  —  The  work  done  by  the 
leaf  involves  the  expenditure  of  energy.  There  are  a  large 
number  of  cells  in  the  maize  leaf  filled  with  minute  green 
bodies,  called  chlorophyll  grains.  These  not  only  give  the 
green  color,  but  arrest  the  energy  of  the  sun's  rays,  making 
use  of  this  energy  to  perform  the  various  activities  of  the 
plant. 

25.  The  flower.  —  The  male,  or  staininate,  flowers  are 
borne  in  the  tassel.  The  anthers  are  three  in  number  and 
filled  with  pollen.  While  the  pollen  sacs  are  small,  about 
one-fourth  inch  in  length,  yet  each  is  estimated  to  contain 
2500  pollen  grains. 

The  female,  or  ^pistillate,  flowers  are  borne  on  the  ear 
and  are  closely  related  in  structure  to  the  male  flowers. 
When  very  young,  they  are  borne  in  pairs,  but  one  is  very 
small  and  seldom  develops.  Occasionally  both  of  these 
grains  develop  in  the  tassel  flowers  of  pod  corns.  Sturte- 
vant "  mentions  also  an  ear  of  podded  flint  corn  from  Ohio, 
in  which  the  kernels  were  twinned.  These  reversions  in- 
dicate that  at  some  time  in  the  early  evolution  of  maize 
both  these  flowers  functioned,  but  for  some  reason  only 
one  now  develops. 

The  principal  parts  of  the  pistillate  flower  are  an  ovary, 
or  egg  cell,  a  carpel  which  surrounds  this  for  protection, 
and  a  long  extension  of  the  carpel,  called  the  style,  or 
*'  silk."     The  details  of  fertilization  are  given  later. 

1  Bessey,  C.  E.     Botany  (Briefer  Course),  p.  45. 

2  Bui.  Torrey  Bot.  Club,  1894  •  336. 


DESCRIPTION   OF  THE   CORN   PLANT  37 

26.  The  ear.  —  The  probable  origin  of  corn  from  some 
grass-like  plant  similar  to  teosinte  is  discussed  under 
Biological  Origin  (p.  15). 

The  ear  may  be  regarded  as  a  branch  of  the  main  stem, 
the  ear  stem  having  exactly  as  many  nodes  as  the  main 
stem  above  the  ear,  the  husks  corresponding  to  the  leaf 
sheaths  and  the  ear  to  the  tassel ;  the  side  branches, 
however,  are  no  longer  present,  while  the  central  spike 
has  been  enlarged  into  a  cob,  and  the  pistillate  flowers,  or 
grains  on  the  ear,  correspond  to  the  pollen  flowers.^ 

The  ear  is  the  storehouse  of  the  maize  plant,  where  is 
produced  not  only  the  young  germ,  but  also  a  store  of 
starch,  protein,  oil,  and  other  products  for  its  future 
nourishment,  much  as  a  swarm  of  bees  makes  a  store  of 
honey  for  the  young,  laying  eggs  in  the  cells  at  the  same 
time.  As  mentioned  heretofore,  these  products  are  first 
prepared  by  the  leaves  and  later  transmitted  to  the  ear. 

References  on  distribution  of  maize  roots  :  — 
Pammel,  L.  H.     Grasses  of  Iowa.     Iowa  Agr.  Exp.  Sta.,  Bui. 

54  : 8-13. 
King,  F.  H.     Wis.  Agr.  Exp.  Sta.,  Rpt.  1892  :  112;    and  1893: 

160. 
Hays,  W.  M.      (1889.)     Minn.  Agr.  Exp.  Sta.,  Bui.  5. 
Ten  Eyck,  A.  M.      (1899-90.)     N.  Dak.  Agr.  Exp.  Sta.,  Bui. 

36:  43. 
Shepperd,  J.  H.      (1905.)     N.  Dak.  Agr.  Exp.  Sta.,  Bui.  64. 
Ten  Eyck,  A.  M.     (1904.)     Kan.  Agr.  Exp.  Sta.,  Bui.  127. 
Colo.  Agr.  Exp.  Sta.,  Rpt.  1896:  181. 
N.  Y.  Agr.  Exp.  Sta.,  Rpt.  1888: 171. 

References  on  tillering  of  maize  :  — 
Neb.  Agr.  Exp.  Sta.,  Bui.  91 :  16. 
Pop.  Sci.  Mo.,  Jan.  1906:55. 

1  What  is  an  Ear  of  Corn  ?     Pop.  Sci.  Mo.,  Jan.  1906. 


CHAPTER  IV 
PHYSIOLOGY   OF  CORN  PLANT 

Plant  physiology  deals  with  the  activities  and  functions 
of  the  physical  parts  of  the  plant.  Not  all  parts  of  a 
plant  have  a  present  important  function.  Certain  parts 
may  be  regarded  as  rudiments  left  in  the  process  of  evo- 
lutionary change,  and  they  may  even  be  detrimental.  In 
other  cases,  certain  parts  may  be  regarded  as  only  chance 
variations  of  no  value  from  an  economic  view  point.  It 
is  therefore  important  to  make  a  careful  analysis  of  plants, 
to  determine  the  function  of  each  part,  which  parts  have 
an  important  function,  and  how  the  proper  activities  of 
the  plant  are  favored  or  hindered. 

27.  Living  plants.  —  One  of  the  distinctive  characters  of 
living  plants  as  compared  with  dead  material  is  the  fact 
that  many  forces  of  nature  may  act  as  a  ''  stimulus  "  and 
get  a  response  entirely  at  variance  with  the  usual  result. 
This  is  well  stated  in  Strasburger  ^  as  follows  :  — 

"The  free  end  of  a  horizontally  extended  flexible  rod  bends 
downwards  merely  by  its  own  weight.  The  same  result  will 
follow  if  any  part  of  a  dead  plant,  such  as  a  dry  stem,  be  substi- 
tuted for  the  rod.  But  if  a  hving,  growing  stem  be  used  in  the 
experiment,  then  the  action  of  gravity  will  manifest  itself  in  a 
manner  altogether  at  variance  with  its  ordinary  operation. 
That  part  of  the  stem  which  is  still  in  a  state  of  growth  will 
ultimately  curve  upwards,  and  hij  its  own  activity  assurne  an  up- 

1  Strasburger,  Noll,  Schenk,  and  Karsten.  (1908.)  Textbook 
of  Botany,  p.  173. 

38 


PHYSIOLOGY  OF  CORN  PLANT  39 

right  position;  it  moves  in  a  direction  exactly  opposite  to  the 
attractive  force  of  gravity.  If  a  tap-root  be  similarly  experi- 
mented upon,  it  will,  on  the  contrary,  continue  its  downward 
movement  until  it  places  itself  in  a  line  with  the  direction  of 
the  attraction;  a  rhizome,  however,  under  like  circumstances, 
would  constantly  maintain  its  growing  apex  in  a  horizontal 
position.  In  these  three  experiments,  the  force  of  gravity  is 
exerted  upon  horizontal  portions  of  plants.  The  physical  condi- 
tions are  the  same  in  each  case,  yet  how  entirely  different  the 
results." 

The  above  phenomena  are  some  of  the  manifestations  of 
"  life."  In  the  same  way,  light,  heat,  moisture,  and 
other  physical  factors  will  act  as  a  ''  stimulus  "  to  living 
plants,  but  the  response  is  not  always  what  would  be  ob- 
tained with  dead  material,  and  it  may  be  the  opposite. 
This  fact  should  be  kept  in  mind  in  dealing  with  living 
plants. 

28.  Stability  of  the  plant.  —  A  corn  plant  one  inch  in 
diameter  at  the  base  may  be  100  to  125  inches  in  height, 
yet  it  will  have  a  broad  spread  of  leaf,  bear  a  heavy  ear, 
and  be  able  to  maintain  itself  without  breaking  or  falling 
prostrate  in  a  heavy  wind.  A  rye  plant  bearing  a  heavy 
head  may  be  five  hundred  times  as  tall  as  the  diameter  of 
its  base.  This 'rigidity  of  the  plant  body  is  necessary  in 
order  that  it  may  reach  considerable  height  and  expand  its 
leaves  to  light  and  air.  Rigidity  is  due  principally  to 
turgidity  in  the  soft  tissue  or  young  plant,  and  to  the 
mechanical  tissues  in  the  older  and  stronger  parts. 

29.  Turgidity.  —  In  the  leaves  of  a  corn  plant  is  a 
certain  set  of  cells,  known  as  bulliform  cells.  These  are 
located  near  the  upper  surface  between  the  ribs,  or  veins. 
(See  Fig.  14.)  When  moisture  is  abundant,  these  cells 
absorb  water  until  they  are  turgid.  The  leaf  is  then 
spread  out  flat  and  is  more  or  less  rigid  and  brittle.     How- 


40  CORN   CROPS 

ever,  when  the  weather  is  very  hot  or  when  soil  moisture 
is  low,  the  cells  lose  water  enough  so  they  are  no  longer 
turgid,  and  the  leaf  then  becomes  limp  and  rolls  up.  In 
the  same  way,  all  cells  of  the  plant  may  be  more  or  less 
turgid,  aiding  in  giving  rigidity  to  the  plant  body. 

30.  Tension.  — ^  If  a  section  a  few  inches  long  of  the 
stem  of  green  corn  be  taken  and  the  outer  peripheral  tissue 
be  removed  from  the  pith,  the  pith  will  at  once  expand  in 
length  and  some  force  will  be  required  to  restore  it  to 
normal  length.  It  will  thus  be  seen  that  there  is  a  natu- 
ral tension  at  all  times  between  the  outer  cortex  and  the 
pith.  '  This  tension  adds  to  the  rigidity  of  the  stem. 

31.  Mechanical  tissue.  —  The  supporting  framework 
is  made  up  of  woody  and  fibrous  tissues  in  the  outer  part 

and  the  nodes  of  the  stem  and  in  the 
midribs  and  veins  of  the  leaves.  These 
are  mostly  comprised  of  fibers  (scleren- 
chyma  or  bast)  of  great  tensile  strength. 
Quoting  from  Strasburger,  "  the  sus- 
taining strength  of  sclerenchymatous 
fibers  is,  within  the  limits  of  their  elas- 
FiG.  15.  —  lUustrat-   ^icity,    in   general   equal    to    the    best 

ing    resistance    to 

bending  when  the    wrought    iron,    or    hammered    steel, 
supporting  tissue  is   ^^e  fibers  are  bound   together,  giving 

on  the   outside   of  i        •     i       i 

the  stem,  as  in  corn,     a  stroilg  elastic  body. 

One  side  must  be        The  location  of  the  framework  on  the 

shortened  and  the  ,    .  ,  , ,  , ,  •       ,  i  ,  c 

other  stretched.  outside,  rather  than  111  the  center,  ot 
the  stem  adds  to  the  rigidity.  For 
example,  if  an  elastic  rod  be  bent  (Fig.  15),  the  inner  side 
is  shortened  and  the  outer  lengthened.  If  a  supporting 
skeleton  be  placed  in  the  center  of  this  rod,  then  the  rod 
is  flexible  and  considerable  bending  would  be  possible 
without  much  resistance  from  the  center ;  but  if  the  sup- 


PHYSIOLOGY  OF  CORN  PLANT 


41 


Composition  of  Corn  Plants 


Green  plants,  six 
weeks  old 


Water 
90% 


Green  plants,  ears 
just  glazed 


Water 


Mature  plants 


Water 
60% 


Composition  of  Dry  Matter.    Percentage  Basis 

T 


Green  plants 
six  weeks  old 

Green  plants 
ears  just  glazed 

Mature  plants 


Fig.  16.  —  Composition  of  corn  plants  at  three  stages  of  growth.  The 
upper  figure  shows  a  progressive  increase  in  percentage  of  dry  matter 
as  the  plant  approaches  maturity.  The  lower  figure  shows  the  pro- 
gressive change  in  character  of  dry  matter. 


42 


CORN   CROPS 


porting  skeleton  be  on  the  outside,  then  much  greater 
resistance  is  offered. 

In  the  root,  however,  the  mechanical  tissue  is  in  the 
center,  thus  allowing  the  root  to  bend  easily  about  among 
obstructions  and  at  the  same  time  giving  pulling  strength. 

32.  Nutrition.  —  Probably  the  most  interesting,  as 
well  as  the  most  important,  knowledge  regarding  the  corn 
plant  is  the  method  by  which  its  supply  of  elements  lor 
growth  is  secured  from  the  soil  and  air,  and  the  factors 
affecting  the  assimilation  and  use  of  such  plant-food. 

THE    COMPOSITION    OF    A    CORN    PLANT 

33.  If  a  green  corn  plant  2  or  3  feet  in  height  be  dried 
in  an  oven  until  all  the  water  has  been  driven  out,  it  will 
be  found  that  about  90  per  cent  of  the  total  weight  is 
water  and  only  10  per  cent  is  solid,  or  dry  matter.  When 
in  the  roasting-ear  stage,  the  plants  are  about  80  per  qent 
water,  and  later,  at  maturity,  60  per  cent. 

TABLE  IX 

Average  Composition  of  Green  Maize  ^ 


Constituent 

Composition 

OF  Fresh 

Plants 

Composition  of  Dry  Matter  at 
Three  Stages 

Six  Weeks 
Per  Cent 

Eprs  just 
Glazed 

Mature 
Plant 

Water       .... 

Ash 

Protein     .... 
Fiber         .... 
Nitrogen    free    ex- 
tract     .... 
Fat       .     .     ,     .     . 

79.0 
1.2 
1.7 
5.6 

12.0 
.5 

17 

27 
17 

35 
15 

10 
14 
22 

50 
4 

6 

9 

25 

57 
3 

1  From  Jenkins  and  Winton,  Office  of  Exp.  Sta.,  U.  S.  Dept.  Agr. 
Bui.  11,  1892. 


PHYSIOLOGY  OF  CORN  PLANT 


43 


■::■:    ASH     FROM    SOIL   l^"  GREEN   WXf  ■'.'\:: 


Fig.  17. —The  source  of  elements  suppljdng  a  maize  plant.  About  10 
per  cent  of  the  green  weight  (50  per  cent  of  dry  weight)  is  carbon. 
About  5  per  cent  is  oxygen  and  4  per  cent  hydrogen.  The  oxygen  is 
derived  from  the  air  in  combination  with  carbon,  from  water  or  from 
oxide  salts.  The  hydrogen  comes  principally  from  water.  Ash  from 
the  soil  equals  about  1  per  cent,  and  nitrogen  ^  per  cent  of  the  green 
weight.  About  80  per  cent  of  the  green  weight  is  water,  not  in  com- 
position. 


44  CORN   CROPS 

The  dry  substance  is  combustible,  and  when  it  is  ignited, 
about  90  to  95  per  cent  will  be  consumed,  leaving  a  residue 
of  ash.  The  combustible  part  consists  principally  of  the 
elements  carbon,  hydrogen,  and  oxygen,  with  a  smaller 
quantity  of  nitrogen.  The  ash  left  is  made  up  of  mineral 
substances  taken  from  the  soil.  Thus,  only  about  one 
per  cent  of  the  weight  of  a  green  plant  comes  from  the  soil. 

34.  The  essential  constituents.  —  There  are  ten  essen- 
tial elements  necessary  to  plants,  one  of  these  coming  from 
the  air,  two  from  water,  and  six  from  the  soil,  while  one 
—  nitrogen  —  comes  indirectly  from  the  air  through  the 
soil.  Carbon  comes  only  from  the  carbonic  acid  gas  of  the 
atmosphere,  hydrogen  and  oxygen  from  water  (oxygen  also 
from  the  air,  and  oxid  salts),  nitrogen  from  the  soils,  as 
nitrates  or  ammonium  salts.  The  other  six  essentials, 
namely,  sulfur,  phosphorus,  potassium,  calcium,  mag- 
nesium, and  iron,  are  taken  from  the  soil. 

Plants  do  not  find  these  elments  in  simple  forms,  but  in  com- 
bination —  for  example,  the  hydrogen  and  oxygen  from  water, 
where  it  is  in  combination  as  H2O,  and  carbon  from  carbon 
dioxid  (CO2).  All  the  minerals,  as  phosphate,  potassium,  and 
the  others,  are  always  found  in  combination.  A  demonstra- 
tion of  how  plants  can  Uve  on  these  minerals  when  in  solution 
may  be  made  by  taking  pure  distilled  water  and  dissolving  the 
following  mineral  salts  (after  V.  D.  Crone) :  — 

Distilled  water 1-2    liters 

Potassium  nitrate 1,0    gram 

Ferrous  phosphate 0.5    gram 

Calcium  sulfate        0.25  gram 

Magnesium  sulfate 0.25  gram 

If  properly  handled,  a  corn  plant  may  be  grown  to  maturity 
in  this  solution. 

In  addition  to  the  "essential"  elements  found  in  the  ash  of 
plants  there  are  also  other  elements,   as  sodium  and  silicon, 


PHYSIOLOGY  OF  CORN  PLANT  45 

found  in  large  quantities ;   but  these  are  probably  not  essential 
to  growth. 

THE   ABSORPTION   OF   WATER 

35.  It  has  been  pointed  out  in  the  text  that  the  water 
absorbed  by  plants  is  a  dilute  solution  of  all  the  soluble 
substances  in  the  soil,  the  absorption  taking  place  through 
the  vast  number  of  root-hairs,  from  which  the  water  solu- 
tion passes  into  the  lateral  roots,  up  the  stem,  and  out 
into  the  leaves.  The  water  passes  up  the  fibrous  bundles 
found  all  through  the  pith.  This  can  be  demonstrated 
by  cutting  off  a  stem  near  the  ground  early  in  the  morn- 
ing, when  root-pressure  is  high.  Water  will  soon  exude 
in  small  drops  wherever  the  fibro-vascular  bundles  are  cut. 
During  the  heat  of  the  day,  root-pressure  is  negative,  and 
no  result  can  be  secured. 

THE    GIVING    OFF   OF   WATER 

36.  Water  loss  ^  from  the  plant  serves  several  functions, 
the  most  important  of  which  is  the  concentration  of  the 
water  solution.  By  constant  evaporation,  of  water  the 
salts  taken  up  in  solution  are  left  in  the  plant,  to  be 
utilized  in  its  growth.  The  leaf  is  so  constructed  as  to 
facilitate  the  giving  off  of  quantities  of  water  and  at  the 
same  time  protect  the  inner  tissues. 

The  leaf  is  covered  with  a  strong  epidermis,  which  has, 
however,  an  enormous  number  of  stomata.  The  number 
in  a  single  corn  leaf  of  average  size  is  estimated  at  sixteen 
to  twenty  milHons.     These  small  openings  are  connected 

1  Water  loss  from  the  plant  is  of  two  kinds,  namely,  transpiration  and 
evaporation.  The  former  is  closely  associated  with  assimilation,  and  the 
amount  of  water  given  off  as  a  result  of  this  process  is  comparatively 
small.  The  greatest  loss  is  by  simple  evaporation,  in  common  with  aU 
objects  exposed  to  dry  air. 


46 


CORN  CROPS 


with  a  series  of  air  spaces  in  the  leaf  so  that  there  is  free 
movement  of  air  into  and  out  from  the  leaf.  Also,  the 
vascular  bundles,  which  deliver  the  water  from  the  roots 
into  the  leaf,  are  spread  out  in  the  leaf  into  a  fine  net- 
work so  that  every  part  is  quickly  supplied  with  water  as 
it  evaporates. 

The  quantity  of  water  evaporated  from  day  to  day 
depends  directly  on  the  conditions  of  climate  and  on  the 
amount  of  leaf  area  exposed.  An  average  corn  plant  has 
about  8  square  feet  of  leaf  surface,  while  a  full  stand  of 
corn  has  a  total  leaf  area  equal  to  twice  the  area  of  land 
on  which  the  corn  is  growing ;  in  other  words  an  acre  of 
land  would  have  about  two  acres  of  leaf  surface.  The 
daily  water  loss  per  plant  varies  from  3  to  10  pounds, 
depending  on  the  humidity  of  the  air  and  on  the  wind, 
just  as  does  any  other  object  or  a  free  water  surface.  The 
following  data,  taken  at  the  Nebraska  Experiment  Station, 
illustrate  the  above  statements  :  — 

TABLE  X 

Daily  Variation  in  Water   Loss   from   Plants   and   Free 

Water  ^ 


Interval  of  24  Hours,  ending 

Water  Loss  per 
Plant 

Water  Loss  from 
Free  Water 

Grams 

Grams 

July  27,  1911      .... 

4550 

454 

July  28,  1911 

2333 

372 

July  29,  1911 

1579 

173 

July  30,  1911 

2802 

232 

July  31,  1911 

3561 

314 

August  1,  1911 

3982 

374 

August  2,  1911 

3419 

311 

August  3,  1911 

2143 

204 

Nebr.  Agr.  Exp.  Sta.,  24th  Ann.  Rpt.,  p.  102.     1911. 


PHYSIOLOGY  OF  CORN  PLANT  47 

ASSIMILATION 

37.  The  taking  up  of  carbon  from  air  and  uniting  it 
with  other  elements  to  form  plant  tissues  is  called  assim- 
ilation. Carbon  is  found  in  nature,  as  coal  or  graphite, 
or  it  is  artificially  prepared  from  wood,  as  charcoal. 
Carbon  is  the  most  important  constituent  of  all  plants, 
composing  about  50  per  cent  of  the  dry  weight. 

Carbon  can  be  demonstrated  by  charring,  that  is,  by  burning 
a  piece  of  maize  stem  without  sufficient  air  for  complete  com- 
bustion, when  other  substances  will  be  driven  off  by  the  heat, 
leaving  the  carbon.  So  much  carbon  is  present  that  the  stem 
will  retain  its  shape  and  structure. 

When  any  substance  is  burned  or  decomposes,  the 
carbon  present  passes  into  the  air  as  carbon  dioxid  (CO2) . 
This  gas  constitutes  about  0.03  per  cent  of  the  atmos- 
phere. 

A  maize  plant  takes  air  into  the  leaves  through  the  air 
pores  (stomata)  and  extracts  the  carbon  dioxid.  The 
air  then  passes  out  again,  carrying  water  and  by-products 
—  often  oxygen  —  of  which  the  plant  should  rid  itself. 

38.  The  necessary  energy  for  maintaining  the  activities 
of  the  leaf  is  derived  from  the  sunlight.  Some  of  the 
leaf  cells  contain  small  green  chlorophyll  bodies.  When 
the  plant  is  in  strong  sunlight,  these  chlorophyll  bodies 
rapidly  accumulate  starch  grains.  If  the  plant  is  placed 
in  darkness,  however,  no  starch  will  be  made. 

In  the  same  way,  we  may  show  the  necessity  of  carbon  dioxid, 
by  placing  growing  plants  in  air  artificially  freed  of  this  gas. 
Even  in  the  presence  of  bright  sunshine,  no  starch  will  be  accu- 
mulated. 

39.  The  by-product  of  assimilation  is  pure  oxygen.  The 
chemical  process  of  the  manufacture  of  starch  from  carbon 
dioxide  and  water,  through  the  activities  of  chloroplasts, 


48  CORN   CROPS 

may  be  illustrated  as  follows,  leaving  out  intermediate 
steps :  — 

6  CO2  +  6  H2O  =  CeHisOe  +  6  O2 
(glucose  +  oxygen) 

C6H12O6  =  CeHioOs  4"  H2O 

(starch  +  water) 

While  the  starch  is  made  in  the  leaves  it  cannot  be  dis- 
tributed in  this  form  to  other  parts  of  the  plant,  as  starch 
is  insoluble.  It  is  therefore  first  converted  into  sugar 
and  in  this  form  is  distributed  to  the  stem,  roots,  ear,  or 
wherever  needed  for  growth.  The  juice  of  a  green  maize 
stem  may  contain  10  per  cent  or  more  of  sugar  during  the 
earing  season,  when  it  is  being  transported  from  leaves  to 
stem  and  ear.  This  soluable  sugar  may  be  converted 
into  many  forms  of  carbohydrate  material,  as  fiber  or 
starch.  In  the  ear  it  is  principally  deposited  again  as 
starch. 

40.  Growth.  —  Following  the  plan  outlined  by  Sachs, 
the  growth  of  a  maize  plant  may  be  divided  into  three 
distinct  phases,  as  :  — 

1.  The  early  growth  period  (embryonic),  in  which  the 
rudiments  of  new  organs  are  formed. 

2.  Elongation  of  the  already  formed  embryonal  organs. 

3.  Period  of  internal  development. 

The  first  period  covers  about  the  first  three  weeks  of 
growth.  A  plant  three  weeks  old  will  have  all  parts,  as 
the  full  number  of  leaves  and  nodes,  most  of  the  main 
roots,  and  embryonic  tassel,  ears,  and  tillers.  From  this 
time  on,  growth  consists  principally  of  the  elongation 
and  development  of  these  parts.  Later  there  is  a  third 
phase,  that  of  internal  development,  as  the  depositing 
of  starch  in  the  ear  and  the  strengthening  of  fibrous 
tissues. 


PHYSIOLOGY  OF  CORN  PLANT  49 

REPRODUCTION 

41.  In  maize,  as  in  most  plants,  nature  has  provided 
for  the  perpetuation  of  the  race  through  the  abundant 
production  of  seeds.     An  average  maize  plant   produces 


Fig.  18.  — An  ear  of  corn  in  full  silk,  just  ready  for  pollination. 


50 


CORN   CROPS 


about  1000  seeds,  usually  all  on  one  ear ;  in  some  varieties, 
however,  tivo  or  more  ears  are  produced. 

42.  Pollen.  —  The  pollen,  or  fertihzing  element,  is  pro- 
duced in  the  tassels  and  usually  begins  falling  one  to  two 
days  before  silking;   there   is  great  irregularity  in  this 


Fig.  19.  —  The  process  of  fertilization  of  the  corn  flower.  Each  embryonic 
grain  produces  a  long  style  or  "  silk."  Each  silk  must  receive  one  or 
more  pollen  grains. 


PHYSIOLOGY  OF  COBN  PLANT  51 

respect,   however,   some    plants    producing    silk    before 
pollen. 

43.  Style.  —  Each  grain  produces  a  style,  or  silk.  The 
grains  about  one-fourth  of  the  way  from  the  base  of  the 
ear  silk  first,  and  the  process  passes  gradually  toward  the 
tip,  the  entire  period  of  silking  requiring  two  to  four  days. 


Fig.  20.  —  Young  corn  kernels  and  silks. 


52 


CORN  CROPS 


44.  Fertilization.  —  For  fer- 
tilization to  take  place,  every 
silk  must  receive  at  least  one 
pollen-grain,  and  fertilization 
is  probably  surer  if  it  receives 
several.  As  the  pollen  is  dis- 
tributed by  wind,  it  must  be 
very  abundant  to  insure  pol- 
lination ;  therefore,  ten  ^to 
twenty  thousand  pollen  grains 
are  produced  to  every  ovary, 
or  embryonic  kernel. 

The  exposed  end  of  the  silk, 
or  style,  is  covered  with  fine 
hairs  and  is  also  adhesive,  so 
that  pollen-grains  readily  ad- 
here when  they  come  in  con- 
tact. It  is  not  necessary  for 
the  pollen  to  fall  on  a  particu- 
lar part  of  the  silk;  it  may 
reach  any  of  the  exposed  sur- 
face. In  fact,  fertilization  has 
been  accomplished  by  placing 
the  pollen  on  the  silk  within 
the  husk. 

Soon  after  a  pollen-grain 
falls  on  a  receptive  silk  it 
sends  out  a  tube,  or  filament. 

Fig.  21.  —  Ear  of  corn  showing  zone 
poorly  fertilized.  The  ear  silks  in 
successive  zones  from  near  the  butt 
toward  the  tip.  Some  unfavorable 
condition  happened  when  this  zone 
was  in  silk. 


PHYSIOLOGY  OF  CORN  PLANT  53 

which  penetrates  the  silk ;  and  soon  the  contents  of  the 
pollen-grain  pass  down  to  the  egg,  in  the  embryonic  seed 
at  the  base  of  the  silk.  Immediately  upon  fertilization, 
the  ovule  begins  a  rapid  growth.  In  case  a  part  of  the 
silk  should  fail  to  receive  pollen,  those  ovaries  will  not 
develop,  and  the  result  will  be  irregular  rows  on  the  ear. 
Sometimes  in  very  hot  and  dry  weather  the  pollen  is 
killed  and  will  not  fertilize.  Also,  insects  such  as  grass- 
hoppers often  eat  off  the  silks,  or  a  part  of  them,  thus 
preventing  fertilization. 

Several  investigators  have  studied  fertilization  and  embryonic 
development  of  the  corn  ovule,  as  Guignard,  Webber,  True,  and 
Poindexter.  No  one  has  reported  observing  the  passage  of  a 
pollen-tube  down  the  silk.  There  is  some  question  as  to  whether 
the  pollen-tube  actually  passes  down  within  the  tissues  of  the 
style,  or  whether  it  may  not  follow  the  slight  depression  or 
groove  on  one  side  of  the  style.  Guignard  calls  the  opening  near 
+he  base  of  the  style  the  "  stylar  canal,"  and  thinks  that  the  pol- 
len-tube enters  this  opening,  but  he  did  not  observe  it.  When 
the  ovule  is  finally  reached,  it  has  not  been  definitely  observed 
at  just  what  point  the  pollen-tube  enters. 

True,  Rodney.     Bot.  Gaz.  18  :  215. 

Poindexter,  C.  C.     The   Development  of  the  Spikelet  and  Grain  of 
Corn.     The  Ohio  Nat.,  Vol.  IV,  No.  1,  Nov.  1903. 


SECTION   II 

PRODUCTION   AS    RELATED    TO    CLIMATE 
AND  SOILS 


CHAPTER   V 
RELATION  OF  CLIMATIC  FACTORS  TO  GROWTH 

The  ability  of  corn  to  yield  is  indicated  by  certain  max- 
imum yields  that  have  been  obtained  under  favorable 
conditions.  Edward  Enfield/  in  1866,  listed  a  number  of 
record  yields  which  had  been  published  between  1840 
and  1866. 

45.  The  average  of  fourteen  record  yields  collected  from 
seven  States  was  145  bushels  per  acre,  two  of  these  records 
being  200  bushels  per  acre.  The  American  Agriculturist  ^ 
records  in  1857  a  yield  of  857^  bushels  on  5  acres,  or  an 
average  yield  of  171 J  bushels  per  acre.  Hartley^  reports 
a  90-acre  field  of  corn  in  Pennsylvania  averaging  130 
bushels  per  acre,  the  same  farmer  having  averaged  100 
bushels  per  acre  for  twelve  years.  The  four  largest 
yields  on  record  are  as  follows :  — 


Year 

Grower 

Place 

Yield 
Bushels 

1857    . 

1889    . 
1889    . 
1910    . 

Dr.  J.  W.  Parker 

Capt.  Z.  J.  Drake 
Alfred  Rose 
Jerry  Moore 

Asylum     Farm,     Co- 
lumbia, S.C. 
Marlboro,  S.C. 
Yates  Co.,  N.Y. 
Winona,  S.C. 

200.3  (a) 
255.1  (b) 
213.0  (c) 

228.7  (d) 

(a)  This  record  has  often  been  mentioned,  but  original  data  to  verify 
it  are  not  available,  (b)  and  (c)  These  records  and  the  method  of  grow- 
ing are  given  in  The  American  Agriculturist,  XLIX,  March,  1890,  p.  122. 
In  each  case  the  yield  is  field  weight  at  husking  and  would  have  to  be 
reduced  at  least  10  per  cent  for  crib  dry  weight,     (d)  Field  weight. 

1  Enfield,  Edward.     (1866.)     Indian  Corn,  p.  54. 

2  The  American  Agriculturist,  XVI :  238.    1857. 

3  Hartley,  C.  P.     (1910.)     U.  S.  Dept.  Agr.,  Farmers'  Bui.  414  :  14. 

57 


58 


CORN  CROPS 


In  all  of  the  above  cases, 
enormous  quantities  of  com- 
mercial fertilizers  and  manures 
were  used,  but  the  instances 
illustrate  the  ability  of  corn 
to  yield  under  the  most  fa- 
vorable soil  conditions. 

The  possible  yield  of  corn  if 
all  conditions,  both  climatic 
and  soil,  were  ideal  for  a  sea- 
son, is  probably  in  advance  of 
any  yield  thus  far  recorded. 
The  average  yield  of  corn  in 
the  United  States  is  26  bushels 
per  acre,  only  a  small  pro- 
portion of  the  possible  pro- 
duction. 

CLIMATIC  FACTORS  AND 
GROWTH 

46.  The  principal  elements 
of  climate  are  sunshine,  heat, 
rainfall,  humidity,  and  wind. 

The  climate  favorable  to 
corn  is  determined  not  so 
much  by  the  amount  as  by  the 
distribution  of  these  factors, 
without  fluctuations  so  great 
as  to  retard  the  growth  or  to 

Fig.  22.  — A  single  corn  plant  bear- 
ing 5  ears.  Demonstrating  the 
productivity  of  corn  in  favorable 
environment. 


CLIMATIC  FACTORS  59 

reduce  vitality.^  For  example,  one  section  might  have 
sufficient  average  rainfall  for  a  normal  crop,  but  if  this 
rainfall  so  fluctuated  that  at  one  season  it  was  excessive  and 
at  another  deficient,  the  normal  crop  might  be  reduced  one- 
half  or  more ;  while  another  region  with  no  more  total 
rainfall  but  a  better  distribution  would  have  a  normal 
crop.  In  the  same  way,  a  single  frost  out  of  season  or  a 
hot  wind  might  do  great  damage,  although  the  average 
temperature  might  appear  favorable.  Average  annual 
rainfall,  temperature,  and  sunshine  are  not  a  safe  guide, 
unless  the  fluctuation  of  these  factors  during  the  growing 
season  is  also  known. 

47.  Length  of  the  growing  season,  —  Corn  differs 
somewhat  from  other  cereals  in  being  able  to  adjust 
itself  to  the  growing  season.  Wheat,  oats,  and  barley 
grown  in  northern  regions  yield  as  well  as  when  moved 
farther  south,  or  even  better.  They  have  a  somewhat 
longer  growing  season  when  taken  south,  but  do  not  oc- 
cupy the  available  period  as  does  corn.  Some  North 
Dakota  varieties  of  corn  will  mature  in  80  days,  while 
Gulf  States  varieties  often  take  200  days.  There  are 
large  corn  regions  with  a  growing  season  of  more  than 
200  days,  but  it  does  not  appear  that  corn  has  been 
able  in  any  region  to  utilize  to  advantage  a  longer 
growing   period. 

As  the  tropics  are  approached,  while  frosts  cease  to 
limit  the  crop-growing  season,  at  the  same  time  there  is 
usually  a  dry  period  which  serves  as  a  limit.  In  Mexico 
the  growing  season  is  limited  in  this  way. 

All  other  factors  being  favorable,  we  may  assume  that 

'  The  effect  of  fluctuation  of  rainfall  on  crop  production  is  discussed  in 
Bui.  130,  Bur.  Plant  Indus.,  U.  S.  Dept.  Agr.,  41-49,  in  an  article  on 
"  Cost  of  Crop  Production  under  Humid  and  Dry  Conditions." 


60 


CORN   CROPS 


the  ability  of  corn  to  yield  will  increase  with  the  length  of 
the  growing  season  up  to  somewhere  near  200  days. 
Therefore,  for  a  good  share  of  the  present  corn-belt  of 
the  United  States,  the  length  of  the  growing  season  is  an 
important  limiting  factor.     However,  the  varieties  most 


_j\ 

—^Bjf^ 

jCw 

/^-l 

A 

4 

\^/7^ 

^^^\ 

/so^ 

\.^ 

S 

==<^ 

3 

1 

1^0 

'^  ^y\ 

no* 

./T 

r^ 

200 

^ 

^      ] 

^^'^S^^s^^ 

if 

^ 

M 

^ 

^3uU-    ^    ^ 

\) 

Fig.  23.  —  Length  of  growing  season  as  indicated  by  the  average  date  of 
last  killing  frost  in  spring  and  first  killing  frost  of  fall.  (Bui.  V.,  U.  S. 
Weather  Bureau.) 

commonly  grown  in  the  South  mature  in  160  to  180  days, 
due  to  other  limiting  factors  than  frost,  such  as  the  rainfall 
not  being  sufficient  for  the  entire  season,  poor  drainage  in 
early  spring,  or  an  unfertile  soil. 

The  accompanying  chart,  taken  from  Bulletin  V  of  the 


CLIMATIC  FACTORS  61 

United  States  Weather  Bureau,  shows  the  average  length 
of  the  crop-growing  season,  or  rather  the  time  between  the 
average  date  of  the  last  killing  frost  in  spring  and  the 
average  date  of  the  first  kilHng  frost  in  fall. 

The  growing  season  of  corn  nearly  coincides  with  the 
last  probable  frost  of  spring  and  the  first  probable  frost  of 
fall.  For  example,  at  Lincoln,  Nebraska,  where  the  aver- 
age time  between  killing  frosts  is  given  as  165  days,  it  is 
not  considered  advisable  to  grow  a  variety  of  corn  taking 
more  than  130  days  to  mature.  The  growing  season  for 
corn  would  be,  in  general,  20  to  30  days  less  than  indicated 
on  the  chart ;  or  the  200-day  limit  would  be  central  South 
Carolina. 

Also,  there  is  great  fluctuation  in  the  length  of  growing 
season  from  year  to  year  at  any  one  point,  and  there  is  a 
general  tendency  to  grow  corn  that  will  mature  in  the 
shortest  season.  Frear  ^  made  a  study  of  meteorological 
conditions  in  relation  to  the  development  of  corn  at  the 
Pennsylvania  station  for  three  ears,  1887  to  1889.  In 
his  conclusions  he  makes  this  statement :  "  The  difference 
in  temperature  between  these  two  seasons  (1887  and  1889) 
is  almost  equal  to  the  difference  in  the  mean  July  tempera- 
ture of  Quebec  and  Boston ;  of  Burlington,  Vermont,  and 
Philadelphia;  and  of  Fort  Assiniboine,  on  the  northern 
boundary  of  the  United  States,  and  Santa  Fe,  New  Mexico. 
Then,  too,  in  1889  the  rainfall  was  almost  twice  as  great  as 
in  1887,  and  the  cloudiness  at  least  25  per  cent  greater." 

48.  Relation  of  sunshine  to  growth.  —  The  function 
of  sunHght  in  furnishing  the  necessary  energy  for  the 
various  activities  of  plant  growth  was  discussed  in  the 

1  Frear,  W.,  and  Caldwell,  W.  H.  Relation  of  Meteorological 
Conditions  to  the  Development  of  Corn.  Penn.  Agr.  Exp.  Sta.,  Ann. 
Rpt.  1889. 


62  CORN   CROPS 

chapter  on  physiology.  This  has  been  well  expressed 
by  Abbe,  as  follows  :  ^  — 

"  The  growth  of  a  plant  and  the  ripening  of  the  fruit 
is  accomplished  by  a  series  of  molecular  changes  in  which 
the  atmosphere,  the  water,  and  the  soil,  but  especially 
the  sun,  play  important  parts.  In  this  process  a  vital 
principle  is  figuratively  said  to  exist  within  the  seed  or 
plant  and  to  guide  the  action  of  the  soil,  the  water,  and 
the  air  into  such  new  chemical  combinations  as  will 
build  up  the  leaf,  the  woody  fiber,  the  starch,  the  pollen, 
the  flower,  the  fruit,  and  seed.  .  .  .  No  plant  life,  not 
even  the  lowest  vegetable  organism,  is  perfected,  except 
through  the  influence  of  the  radiation  from  the  sun.  .  .  . 
The  radiation  from  any  artificial  light,  especially  the  most 
powerful  electric  light,  will  accomplish  results  similar  to 
sunlight ;  therefore  it  is  not  necessary  to  think  that  life, 
or  the  vital  principle,  is  peculiar  to  or  emanates  from  the 
sun,  but  on  the  contrary  that  living  cells  utilize  the  radia- 
tions or  molecular  vibrations  so  far  as  possible  to  build 
up  the  plant." 

49.  The  intensity  of  sunlight.  —  The  intensity  of  the 
sunlight  received  on  the  earth's  surface  is  modified  by  the 
altitude  of  the  sun,  which  determines  the  total  hours  of 
sunshine  duration,  by  the  atmosphere,  and  by  the  clouds. 

At  high  noon  on  a  perfectly  clear  day,  if  there  were  no 
atmosphere,  the  earth's  surface  would  receive  the  full 
effect  of  the  sun's  rays.  When  the  sun  is  at  zenith  the 
atmosphere  absorbs  about  12.5  per  cent  of  the  sun's 
energy,  so  the  efficiency  may  be  expressed  as  .875,  assum- 
ing the  full  effect  to  be  1.  However,  the  sun  is  only  at 
zenith  for  a  moment,  therefore,  as  it  approaches  the  hori- 

1  Abbe,  Cleveland.  Relations  between  Climates  and  Crops.  U.  S. 
Weather  Bureau,  1905  :  15. 


CLIMATIC  FACTORS 


63 


zon,  the  altitude  decreases,  until  at  the  horizon  the  light 
must  penetrate  12  to  35  times  as  much  atmosphere,  and 
its  total  effect  is  weakened  to  about  one-filth  the  full 
effect  at  90  degrees.  The  effect  at  different  altitudes  is 
expressed  in  the  following  selected  altitudes  :  ^  — 

TABLE  XI 


Altitude  of  Sun 
Degrees 

Thickness  of 

Atmosphere 

Laplace  Formula 

Intensity  of  Direct 

Sunshine;    Calories  per 

Minute,  per  Sq.  Cm. 

ON  Surface  Normal  to  Rays 

0 

4 

10 

30     „ 

50 

90 

35.50 
12.20 
5.70 
1.995 
1.305 
1.000 

0.359 
1.293 
1.868 
2.275 
2.364 
2.403 

From  the  equator  to  40  degrees  latitude,  the  total  sun- 
shine received  at  a  given  place  from  March  to  September 
is  about  one-third  of  the  total  possible  sunshine  at  that 
point  if  the  sun  stood  at  zenith  during  the  hours  of  day- 
light. In  the  northern  latitudes  the  longer  days  of  mid- 
summer compensate  for  the  lower  altitudes  of  the  sun,  so 
that  during  the  months  of  June  and  July,  as  much  heat 
is  received  at  the  north  pole  as  at  any  lower  altitude. 
In  fact,  for  a  period  of  about  90  days,  more  heat  units 
are  received  at  the  north  pole  than  the  equator,  but  due 
to  the  great  amount  of  ice  is  not  sufficient  to  raise  the 
temperature  above  freezing.  The  relative  quantities  of 
heat  received  at  different  latitudes  in  the  Northern  Hemi- 
sphere are  shown  by  the  following  table,  as  calculated  by 
Aymonnet :  ^  — 

1  Abbe,  loc.  cit.,  p.  85.  ^  Ibid.,  p.  92. 


64 


CORN  CROPS 
TABLE   XII 


Latitude 

0° 

10° 

30° 

50° 

70° 

80° 

90° 

March  20-31       .     . 

April 

May 

June 

July 

August       .... 
September  1-23 

3.7 

10.0 

9.8 

9.2 

9.7 
10.1 

7.7 

3.7 
10.6 
10.7 
10.4 
10.7 
10.7 

7.8 

3.3 
10.1 
11.7 
11.9 
12.1 
10.9 

7.1 

2.3 

8.0 

10.5 

11.3 

11.3 

9.2 

5.2 

1.1 
5.4 
9.0 
10.7 
10.3 
6.8 
2.7 

0.6 
3.9 
8.6 
11.0 
10.1 
5.9 
1.5 

0.2 
3.4 
8.7 
11.1 
10.2 
5.8 
0.9 

Total      .... 

60.2 

64.6 

67.1 

57. S 

46.0 

41.6 

40.3 

Total  possible   if 
sun    stood     at 
zenith     .     .     . 

186.0 

186.0 

186.0 

186.0 

186.0 

186.0 

186.0 

It  is  apparent  from  the  above  data  that  up  to  70  degrees 
north  latitude  there  is  sufficient  sunshine  during  the 
summer  months  to  produce  corn,  were  it  not  for  other 
Hmiting  factors,  as  low  temperature  due  to  a  cold  soil  and 
cold  air  currents. 

The  data  presented  thus  far  are  on  the  basis  of  per- 
fectly clear  days,  but  the  presence  of  clouds  reduces  the 
sunshine.  At  Montsoris,  France,  careful  records  for  the 
corn-growing  season  kept  from  1875  to  1885  showed 
only  about  40  per  cent  of  the  possible  intensity  of  sunshine, 
due  to  cloudiness.  Corn  under  such  conditions  does  not 
grow  well,  but  requires,  even  at  that  latitude,  what  might 
be  termed  a  rather  "  sunny  "  climate. 

We  may  conclude  that  except  where  cloudiness  prevails 
for  half  the  time,  there  is  sufficient  sunshine  for  corn  pro- 
duction even  up  to  70  degrees  latitude. 

50.  Relation  of  rainfall  to  growth.  —  The  transpiration 
of  14  to  20  tons  of  water  is  required  to  produce  one  bushel 


CLIMATIC  FACT0E8 


65 


of  corn.  For  a  yield  of  50  bushels  per  acre,  this  equals 
7  to  10  acre-inches  of  water.^  With  a  larger  crop  the  water 
used  would  be  increased  proportionally.  Under  field  condi- 
tions there  must  be  added  to  this  whatever  loss  may  take 
place  through  run-off,  evaporation  from  the  soil,  and 
seepage.     King  found  that  a  yield  of  7000  to  8000  pounds 

Jfoij     Ju^e      Jultj    JiLLC,     Seii, 


•\t 

5J-, 

~/      " 

—     \  ' 

^r 

— -    y 

\ 

fTZ^^ 

—  ~ 

z=n.= 

—.     "■* 

^ 
^ 

==V^ 

T 

^ 

«> 

-.^ 

/ 

z        ~- 

/ 

^•^ 

^i^ 

Fig.  24.  —  Chart  showing  relation  between  storage  water  in  the  soil  and 
consumption  of  water  by  the  corn  plant  each  month.  The  storage 
capacity  of  the  soil  is  exhausted  before  the  end  of  July.  The  crop  is 
therefore  dependent  on  July  and  August  rainfall. 


of  dry  matter  per  acre  (approximately  a  50-busheI  yield) 
required  about  12  acre-inches  under  field  conditions.  In 
this  case  the  loss  by  seepage,  run-off,  and  evaporation 
must  have  been  about  5  acre-inches  (assuming  7  inches 
used  by  the  crop),  but  this  will  vary  with  the  soil,  culti- 
vation, distribution  of  rainfall  during  the  growing  season, 
and  amount  of  storage  water  in  the  soil  at  planting  timeo 

1  Montgomery,  E.  G.     Ann.  Rpt.  Nebr.  Agr.  Exp.  Sta.  1901  :  155. 
King,  F.  H.     Ann.  Rpt.  Wis.  Agr.  Exp.  Sta.  1903  :  99. 
F 


66  CORN  CROPS 

An  average  corn  soil  in  good  tilth  will  store  about  5  to 
6  inches  of  available  water  in  the  upper  4  feet.  A  50- 
bushel  crop  would  then  require  at  least  6  inches  addi- 
tional rainfall  during  the  growing  season,  and  prob- 
ably more  than  this,  as  corn  seldom  grows  well  when 
required  to  exhaust  the  soil  moisture  to  low  limits.  A 
75-bushel  crop  would  require  an  additional  rainfall  of 
10  inches  and  a  100-bushel  crop  at  least  15  inches  during 
the  growing  season,  in  addition  to  that  stored  in  the  soil. 
When  the  run-off  is  large,  as  on  hills  or  with  torrential 
rains,  or  when  there  is  seepage,  the  above  estimate  should 
be  increased.  This  estimate  is  on  the  assumption  that 
the  soil  is  fertile.  No  amount  of  rain  would  make  a  poor 
soil  productive.  For  example,  the  average  rainfall  for 
June,  July,  and  August  in  the  eight  surplus  corn  States 
is  about  12  inches,  but  the  average  yield  is  28.5  bushels. 
Other  factors  than  total  rainfall  here  limit  the  yield, 
one  important  factor  being  that  the  rainfall  is  not  always 
properly  distributed. 

51.  Any  system  of  culture  that  will  serve  to  prevent 
run-off  on  the  one  hand  and  to  decrease  evaporation  on 
the  other,  will  proportionally  increase  the  available  water 
supply  for  the  crop. 

Not  only  the  total  amount,  but  the  distribution,  of  the 
season's  rainfall  is  of  great  importance.  Figure  25  shows 
the  precipitation  for  June,  July,  and  August  for  a  period 
of  fifteen  years  and  the  yield  for  eight  surplus  corn  States, 
namely,  Ohio,  Indiana,  Illinois,  Iowa,  Nebraska,  Kansas, 
Missouri,  and  Kentucky.^ 

Here  is  shown  a  very  close  relationship  between  rainfall 
and  yield,  when  large  areas  are  considered. 

1  Smith,  J.  Warren.  Relation  of  Precipitation  to  Yield  of  Com 
U.  S.  Dept.  Agr.  Year  Book,  1903  :  215-224. 


CLIMATIC  FACTORS 


67 


Professor  Hunt/  at  the  Illinois  Agricultural  Experiment 
Station,  grew  18  plats  of  corn  which  yielded  32  bushels 
per  acre.  The  next  year,  and  on  the  same  plats  and  with 
the  same  varieties  of  corn,  the  yield  was  94  bushels  per 
acre.  The  rainfall  from  May  to  September  was  13  inches 
the  first  season  and  22.5  inches  the  second  season. 


] 

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00    c 

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Fig.  25.  —  Rainfall  of  June,  July,  and  August,  and  yield  of  corn  per  acre. 
(Year  Book,  U.S.  Dept.  Agr.,  1903.) 

Average  yields  of  corn  1888  to  1902. 

Average  rainfall  for  June,  July,  and  August. 


The  seasonal  rainfall  and  its  distribution  is  the  most 
important  climatic  factor  in  corn  production.  With  suffi- 
cient rainfall,  'properly  distributed,  it  is  probable  that  the 
present  yield  of  corn  would  be  increased  50  to  100  per  cent. 
We  cannot  control  the  rainfall  or  its  distribution  during 
the  season,  therefore  farm  practice  must  make  the  best 
use  of  rainfall  as  it  comes.  The  present  rainfall  is  suffi- 
cient for  two  to  three  times  the  present  yield,  if  it  is  con- 
served and  the  soil  is  in  the  most  fertile  condition. 

1  Hunt,  T.  F.     Cereals  in  America,  p.  207. 


CHAPTER  VI 
RELATION  OF  SOILS    TO  GROWTH 

Most  of  the  good  corn  soils  of  the  United  States  are 
deep  black  loams,  well  drained,  well  supplied  with  organic 
matter,  and  rich  in  available  nitrogen,  phosphates,  and 
potassium. 

52.  The  soil  may  be  regarded  as  a  medium  for  holding 
minerals  and  water  in  an  available  form  for  the  plants  as 
needed.  Natural  productive  soils  are  those  that  in  a 
state  of  nature  contain  all  the  mineral  elements  and  organic 
matter  necessary,  and  are  supplied  with  sufficient  natural 
rainfall. 

In  some  virgin  soils,  as  the  deep  black  loam  soils  of  the 
Mississippi,  Ohio,  and  Missouri  river  drainage  basins, 
there  is  sufficient  of  all  mineral  elements  in  an  available 
form  for  the  maximum  production  of  corn.  Even  in 
these  soils,  however,  maximum  production  is  seldom  at- 
tained, as  the  rainfall  is  not  always  properly  distributed, 
nor  even  sufficient. 

Corn  especially  enjoys  a  large  supply  of  nitrogen  and 
will  flourish  in  soils  so  rich  in  available  nitrogen  that  other 
cereal  crops  would  produce  an  excessive  amount  of  straw, 
probably  lodging  and  making  a  poor  yield  of  grain.  Corn 
is  able  to  make  use  of  fertility  furnished  through  the  de- 
caying of  coarse  organic  matter,  as  manure  or  sod  land ; 
while  other  cereals,  as  wheat  and  oats,  require  for  best 
results  a  more  advanced  state  of  decomposition,  with 
the  elements  more  easily  available. 

68 


BELATION  OF  SOILS   TO   GROWTH 


69 


The  ability  of  corn  to  utilize  to  advantage  large  quan- 
tities of  fertilizer  and  manure  is  illustrated  in  the  cases 
cited  on  page  57  of  the  four  maximum  yields  of  corn 
produced. 


Fig.  26.  —  Corn  as  it  grows  on  the  best  type  of  natural  corn  land. 


70  CORN  CROPS 

CAUSES    OF   LOW    PRODUCTION 

53.  Assuming  rainfall  to  be  sufficient,  a  good  corn  soil 
should  produce  75  bushels  per  acre.  Only  a  small  per- 
centage of  the  corn  land  in  the  United  States  will  yield 
this  at  present,  due  to  certain  causes  which  may  be 
summarized  as  follows  :  — 

1.  Poor  drainage.  Corn  suffers  more  than  do  other 
cereals  from  poor  drainage,  as  it  requires  a  "  warm  " 
soil,  and  also  available  nitrogen  in  rather  large  quantities. 
Nitrifying  processes  are  hindered  in  waterlogged  soils. 

2.  Surface  soil  depleted  through  erosion,  very  com- 
mon on  rolling  lands  in  regions  of  large  rainfall. 

3.  Soil  once  fertile  but  depleted  through  constant  crop- 
ping without  return  of  organic  matter  or  minerals. 

4.  Soils  which  in  a  virgin  state  were  deficient  in  organic 
matter  or  lacking  in  some  mineral  element. 

Each  of  the  above  soils  will  be  found  deficient  in  one 
or  more  of  the  following  :  — 
(a)  Drainage. 
(h)  Organic  matter. 

(c)  Nitrogen. 

(d)  One  or  more  mineral  elements. 

(a)  is  corrected  by  drainage,  (b)  and  (c)  by  manure  or 
the  growing  of  legumes,  (d)  by  manure  or  commercial 
fertilizers. 

CLASSIFICATION    OF    CORN    SOILS    IN    THE     UNITED     STATES 
ACCORDING    TO    PRODUCTIVENESS 

54.  For  the  regions  east  of  the  Rocky  Mountains  the 
corn  soils  may  be  classed  according  to  productivity  into 
four  general  groups. 

1.  Soils  capable  of  producing  75  bushels  or  more  per 


RELATION   OF  SOILS   TO   GROWTH  71 

acre,  with  normal  rainfall  of  region  such  as  the  black 
loam  bottom  land  soils  of  the  Mississippi  drainage  basin, 
and  certain  areas  of  black  upland  or  drained  swamps. 
This  soil  is  well  drained,  well  supplied  with  organic  mat- 
ter, minerals,  and  rainfall,  and  usually  commercial  fertil- 
izers will  show  little  or  no  effect.  The  total  area  is  small, 
probably  not  greater  than  1  per  cent  of  the  Corn  Belt. 
This  may  be  termed  the  ideal  corn  soil. 

2.  Soils  producing  35  to  50  bushels  per  acre,  with  favor- 
able climatic  conditions. 

(a)  This  includes  the  greater  part  of  the  cultivated 
lands  in  the  surplus  corn  States  of  Ohio,  Indiana,  Illi- 
nois, Iowa,  Nebraska,  Kansas,  and  Missouri.  These 
soils  have  been  cropped  for  fifty  to  seventy-five  years, 
during  which  time  the  abihty  to  yield  has  decreased 
25  to  50  per  cent.  All  these  soils  respond  quickly  to  an 
application  of  manure,  or  are  increased  25  to  50  per  cent 
in  productivity  by  growing  a  crop  of  clover  or  alfalfa. 
They  seem  to  need  organic  matter  and  available  nitrogen 
more  than  anything  else.  The  supply  of  minerals  is  gen- 
erally sufficient,  but  in  many  cases  the  application  of  both 
potassium  and  phosphates  gives  increased  yields,  though, 
as  a  general  rule,  the  increase  is  not  sufficient  to  be  profit- 
able. Rotation,  the  use  of  legumes,  and  manure  are  to 
be  relied  on  at  present  as  the  principal  means  of  main- 
taining or  increasing  the  yield. 

(b)  All  the  "  good  corn  land  "  through  the  Eastern  and 
Southern  States  is  also  included  in  this  class. 

3.  Land  producing  25  to  35  bushels  under  favorable 
climatic  conditions. 

(a)  Through  the  Eastern  and  Southern  States  are 
large  areas  which  are  fairly  productive  when  first  brought 
under    cultivation,    but    which    have    been    cropped    for 


72  CORN  CROPS 

seventy-five  years  or  more.  Erosion  also  has  played  an 
important  part  in  depleting  the  rolling  lands.  The 
supply  of  organic  matter  is  generally  low,  and  in  many 
cases  the  lands  need  underdrainage.  Throughout  the 
"  Corn  Belt  "  there  are  also  considerable  areas  in  this 
class. 

(6)  Soils  naturally  not  very  productive,  through  lack 
of  one  or  more  mineral  elements  or  of  drainage. 

In  general,  legumes  and  manure  must  be  the  principal 
means  of  increasing  and  maintaining  the  productivity 
of  this  land ;  but  when  a  mineral  element  is  lacking,  as 
lime,  potassium,  or  phosphorus,  it  will  usually  be  neces- 
sary to  add  this  in  the  form  of  commercial  fertilizer. 

4.  Land  producing  less  than  20  bushels  per  acre. 

(a)  Through  the  Eastern  and  Southern  States  are  large 
areas  which,  through  continuous  cropping  and  erosion, 
are  low  in  yield.  In  addition  to  the  prevention  of  ero- 
sion, the  same  general  treatment  as  is  recommended  for 
the  previous  class  may  be  used. 

(6)  Land  in  regions  of  deficient  rainfall.  Where  there 
is  less  than  eight  inches  during  the  growing  season,  lack 
of  moisture  becomes  a  limiting  factor  in  corn  production. 
From  Dakota  to  Texas  there  is  a  large  area  with  a  fertile 
soil  but  an  annual  rainfall  of  only  18  to  25  inches.  In 
these  soils  conservation  of  moisture  is  the  most  important 
phase  of  soil  treatment. 

SUMMARY 

55.  The  abihty  of  corn  to  yield  is  indicated  by  certain 
maximum  yields,  when  150  to  200  bushels  per  acre  have 
been  harvested.  Regarding  climatic  factors,  there  is 
usually  enough  sunshine  and,  in  most  of  the  Corn  Belt, 
a  sufficient  total  rainfall ;   but  the  latter  is  not  often  dis- 


RELATION  OF  SOILS   TO   GROWTH  73 

tributed  in  the  best  way  for  the  growth  of  corn.  A  large 
share  is  lost  by  run-off,  and  the  supply  is  seldom  properly 
conserved  by  preparation  of  the  land  and  by  cultivation. 

The  length  of  growing  season  is  a  limiting  factor,  where 
the  season  is  less  than  180  days. 

The  principal  cause  of  low  production  is  lack  of  avail- 
able fertihty  in  the  soil. 

Climatic  factors  are  mostly  out  of  our  control  except 
that  the  effect  of  rainfall  may  be  modified,  hence  our 
principal  efforts  in  increasing  corn  production  should  be 
in  the  treatment  of  soil. 


SECTION   III 

IMPROVEMENT  AND  ADAPTATION  OF  THE 
CORN  PLANT,  AND  ENVIRONMENT 


CHAPTER  VII 
EARLY  CULTURE  OF  CORN 

Indian  corn  was  unknown  to  Europeans  until  the 
discovery  of  America.  At  that  time  it  was  found  to  be 
in  general  cultivation  by  the  Indians  of  both  North  and 
South  America.  In  fact,  corn  was  the  principal  crop 
cultivated  by  the  native  Americans,  as  they  had  neither 
oats,  wheat,  nor  barley,  and  very  few  of  the  cultivated 
vegetables.  The  most  ancient  evidence  of  the  culture 
of  corn  is  found  on  the  western  coast  of  South  America 
and  in  Mexico.  In  Peru  specimens  of  corn  have  been 
found  in  connection  with  ancient  ruins  or  geological  forma- 
tions, which  are  probably  at  least  two  or  three  thousand 
years  old.  The  fact  that  corn  was  buried  in  the  tombs,  as 
well  as  other  evidence,  indicates  that  it  had  an  important 
place  in  the  religious  ceremonies  of  this  semicivilized 
people  and  was  probably  their  most  important  cultivated 
plant. 

56.  During  the  fifteenth  century  the  earliest  white  ex- 
plorers of  America  took  corn  back  to  Europe,  where  in 
time  it  came  to  be  extensively  cultivated,  especially  in 
those  countries  surrounding  the  Mediterranean  Sea. 
'  When  corn  culture  began  to  spread  in  Europe  it  had 
many  curious  names,  as  Italian  corn,  Turkish  corn, 
Spanish  wheat,  Guinea  wheat,  and  others,  probably  indi- 
cating the  places  where  its  culture  first  became  extensive. 

Collins  has  recently  described  a  type  of  corn  cultivated 

77 


78  COBN  CROPS 

in  China.  References  to  corn  in  Chinese  literature  indi- 
cate its  culture  in  China  for  some  350  years,  although 
just  how  or  when  corn  was  introduced  into  China  is  a 
question. 

When  the  first  white  settlers  came  to  America,  at 
Jamestown  (1607)  and  Plymouth  (1620),  they  at  once  took 
up  the  culture  of  corn,  procuring  the  seed  and  learning  the 
method  of  culture  from  Indians.  It  soon  became  the 
most  important  cereal  crop  of  the  colonists,  gaining  its 
popularity  by  reason  of  its  simple  culture,  its  sure  produc- 
tion, and  the  ease  with  which  the  crop  was  harvested  and 
preserved. 

DEVELOPMENT    OF   VARIETIES 

57.  In  1898  Sturtevant  listed  507  named  varieties  and 
163  synonyms.  It  was  not  possible  for  Sturtevant  to 
secure  all  varieties  in  his  day,  and  it  is  probable  that  a 
complete  catalogue  of  all  varieties  at  present  would 
almost  double  this  number.  Of  these  varieties  listed  by 
Sturtevant,  323  were  classified  as  dent  corn,  69  as  flint 
corn,  63  as  sweet  corn,  27  as  soft  corn,  and  25  as  pop  corn. 

It  is  known  that  at  least  a  few  varieties  of  all  the  five 
principal  groups  were  in  cultivation  when  America  was 
discovered,  with  the  possible  exception  of  sweet  corn. 
The  earliest  record  we  have  of  sweet  corn  is  in  1779,  when 
it  was  mentioned  as  being  in  cultivation  near  Plymouth, 
Mass.^  However,  it  could  easily  have  been  overlooked 
by  the  early  explorers  and  has  probably  been  in  existence 
for  a  long  period. 

It  appears  that  the  Indians  inhabiting  what  is  now  the 
northern  part  of  the  United  States  and  southern  Canada 

I  Sturtevant,  E.  L.      U.   S.   Dept.  Agr.,  Office  of  Exp.  Sta.,  Bui. 

67  :  18. 


EARLY  CULTURE  OF  CORN  79 

cultivated  mostly  an  eight-rowed  flint  corn,  and  in  a 
limited  way  an  early  variety  of  soft  corn  commonly  known 
to-day  as  "  squaw  "  corn.  The  Indians  of  the  south- 
western United  States,  Mexico,  and  South  America  cul- 
tivated the  different  varieties  of  soft  corn  principally, 
and  also,  in  a  limited  way,  flint  corn,  pop  corn,  and  dent 
corn.  The  dent  corn,  however,  does  not  appear  to  be  like 
our  modern  dent  of  the  deep-grained,  large-eared  varieties, 
such  as  Boone  County  White,  but  of  a  rather  shallow- 
grained  type  with  a  square  grain  or  a  grain  even  broader 
than  long.  There  was  also  a  very  rough,  deep-grained 
type  with  a  short  ear,  similar  to  our  Shoe  Peg  corn  of  the 
present  day. 

By  the  year  1800  there  were  a  number  of  recognized 
varieties  of^nt  corn,  mostly  of  eight-rowed  types,  and 
a  few  dent  and  soft  corns  cultivated  by  the  colonists. 
At  least  one  variety  of  sweet  corn  (the  Papoon  eight- 
rowed)  and  a  few  pop  corns  were  known,  but  were  not 
in  general  cultivation. 

Bonafous,  in  1836,  and  Metzger,  in  1841,  both  published 
classifications  and  descriptions  of  corn  indicating  that  at 
least  all  the  characters  of  corn  known  at  present  were  to 
be  found  among  the  varieties  at  that  time.  Metzger 
made  twelve  races,  and  mentioned  varieties  ranging  in 
height  from  18  inches  to  18  feet.  Since  1840  there  has 
been  a  rapid  expansion  of  corn  culture  and  great  interest 
has  been  shown  in  the  development  of  varieties  adapted 
to  various  conditions  and  uses.  It  may  be  safely  estimated 
that  perhaps  three-fourths  of  the  present  varieties  of  corn 
have  been  developed  since  1840.  The  history  of  sweet 
corn  is  an  excellent  example.  Following  are  listed  the 
authorities  and  the  number  of  varieties  of  sweet  corn  that 
each  knew,  and  the  year  of  his  observation :  — 


80 


CORN   CROPS 


Date 


1779 

1832 
1836 
1853 

1858 
1866 

1884 
1898 


Authority 


Bridgman       .... 

Bonafous 

U.  S.  Patent  Office  Rpt. 

Klippert 

Burr 

Sturtevant       .... 
Sturtevant       .... 


Number  op 
Varieties 


1 
1 
1 

3 

6 

12 

33 

63 


There  has  been  a  similar  rapid  development  of  dent 
varieties. 

In  1866  Edward  Enfield  ^  made  a  list  and  description  of 
corn  varieties,  which  he  said  represented  ''  most  of  the 
varieties  in  use,  and  all  that  are  likely  to  be  of  practical 
value  to  the  farmer."  Of  field  corns  he  describes  20 
varieties,  13  of  which  were  flints,  3  broad-grained  dents  of 
12  or  14  rows,  1  flour  corn,  and  3  gourd  seed  varieties 
grown  in  the  South.  However,  J.  S.  Leaming  had  begun 
selecting  "  Leaming  "  corn  in  1826  and  Mr.  Reid  began 
selecting  his  corn  in  the  late  forties.  With  the  rapid  de- 
velopment of  corn  culture,  after  the  Civil  War,  the  modern 
dent  type  came  to  be  generally  used  throughout  the  Corn 
Belt  States ;  although  the  flint  corns  are  still  the  principal 
corns  in  the  Northern  States,  where  the  season  is  too 
short  for  the  large  dents. 

58.  Early  methods  of  modifying  varieties.  —  Probably 
the  means  that  has  been  most  commonly  used  in  the  past 
was  either  to  hybridize  two  varieties  and  select  some  type 
from  this  hybrid  for  several  years  until  the  type  was  fixed, 


1  Enfield,  Edwaed.    (1866.)    Indian  Corn. 
York. 


D.  Appleton  &  Co.,  New 


EARLY  CULTURE  OF  CORN  81 

or  to  start  a  systematic  selection  in  some  recognized  variety. 
One  of  the  earliest  reports  of  the  origin  of  a  variety  is 
given  by  Mr.  C.  H.  Heydrick,  of  Utica,  Penn.,  in  the  Agri- 
cultural Report  of  the  Commissioner  of  Patents  for  1853. 
As  most  early  varieties  were  originated  by  some  such 
method,  the  quotation  is  here  given :  — 

"With  regard  to  the  changes  which  may  be  wrought  in  a 
variety  by  cultivation,  I  cannot  give  a  better  illustration  than 
the  history  of  the  'Vermont  Yellow,'  that  I  cultivated  a  few  years 
ago.  Its  characteristics  were,  a  short  stalk,  slender  above  the 
ear,  strong  below,  ears  small,  with  eight  rows,  thick  at  the  butt 
end,  growing  near  the  ground,  and  frequently  having  a  stem  two 
feet  in  length.  My  plan  of  selecting  seed  from  this  variety  was 
to  choose  from  such  stalks  as  produced  two  or  more  ears,  reject- 
ing those  with  large  butt  ends,  and  such  as  were  not  set  close  to 
the  stalk.  Such  seed  was  hard  to  find  the  first  year.  The  second 
year  nearly  one-half  of  the  stalks  produced  two  ears,  and  there 
were  fewer  long  stems  and  large  butt  ends.  A  milder  climate 
had  also  produced  another  change.  Many  ears  appeared  with 
ten  or  twelve  rows.  This  induced  me  to  improve  the  size  of 
the  corn  and  accordingly  I  selected  as  before,  adding  such  ears 
as  contained  more  than  eight  rows,  together  with  a  few  ears 
of  a  larger  sort.  Continuing  this  system  for  a  few  years  I  ob- 
tained a  variety  characterized  by  the  following  marks :  stalks 
light,  seldom  exceeding  six  feet  in  height ;  strong  below  the  ears, 
slender  above ;  ears  containing  from  ten  to  fourteen  rows,  and 
from  two  to  three  ears  to  a  stalk,  more  frequently  than  a  less  num- 
ber. From  these  facts  it  will  be  seen  that  a  mixed  variety  may 
be  produced,  possessing  all  the  desirable  qualities  of  several 
old  ones.  But  such  a  new  variety  will  require  attention  a  few 
years,  to  prevent  it  from  degenerating  into  one  of  the  original 
sorts,  after  which,  I  think,  the  variety  will  become  as  permanent 
as  any  other." 

Many  of  the  early  corn  breeders  used  the  above  method 
of  selecting  out  some  type  from  an  old  variety.  It  is 
probable,  however,  that  many  of  the  variations  found 


82 


CORN  CROPS 


were  due  to  natural  hybridization,  as  this  is  likely  to  take 
place  to  some  extent  in  a  neighborhood  where  any  two  fields 
are  less  than  twenty  to  forty  rods  distant  from  each  other. 


Fig.  27.  —  Relation  of  type  to  climate.  The  short  type  on  left  is  better 
adapted  to  dry  regions  than  the  tall,  more  slender  type.  The  tall 
type  is  adapted  to  warm,  more  humid  regions. 

Crossing  as  a  means  of  securing  new  forms  was  often 
practiced,  and  a  method  is  outlined  by  Enfield  (1866).^ 

1  Enfield,  Edward.     (1866.)     Indian  Corn,  pp.  70-74. 


EARLY  CULTURE  OF  CORN  83 

59.  Natural  selection  and  acclimatization  in  producing 
varieties.  —  It  is  well  known  that  each  region  of  the  United 
States  has  corn  of  a  type  more  or  less  peculiar  to  that 
section.  For  example,  in  the  Gulf  States,  corn  grows 
very  tall,  frequently  15  to  18  feet,  with  ears  6  or  8  feet 
from  the  ground ;  in  the  Corn  Belt  States  the  plant  is 
about  two-thirds  as  high ;  while  along  the  Canadian  border 
the  height  is  5  to  8  feet,  and  ears  are  often  less  than  2  feet 
from  the  ground.  Also  the  growing  season  will  vary  from 
200  days  in  the  South  to  80  days  in  the  North.  If  a 
variety  of  corn  be  moved  from  one  section  to  another,  it 
will  become  from  year  to  year  more  like  the  native  corn 
of  the  region. 

It  is  not  known  how  much  of  this  change  may  be  due 
to  actual  modification  of  the  plant  by  environment,  but 
it  is  probable  that  it  is  brought  about  chiefly  through 
wide  variations  and  through  both  natural  and  artificial 
selection.  When  a  variety  is  moved  from  one  climate  or 
soil  to  another,  it  does  not  yield  so  well  the  first  year  as 
later,  when  it  becomes  "  acclimatized."  When  planted 
first  in  the  new  location,  there  are  certain  plants  much 
better  suited  than  others  to  the  new  conditions.  These 
would  produce  the  best  ears  and  be  selected  for  seed,  thus 
preserving  the  best-adapted  type.  An  excellent  example 
is  cited  from  Nebraska,^  where  a  variety  of  corn  from 
Iowa  was  grown  in  central  Nebraska  for  two  years  and 
as  a  result  decreased  about  12  inches  in  height,  while  the 
ear  was  almost  8  inches  lower;  the  yield  of  grain,  how- 
ever, increased. 

If  the  same  variety  be  widely  distributed  and  grown 
for  a  few  years,  and  seed  again  collected  for  compari- 
son  under   the   same   conditions,    it  will  be  found  that 

1  Nebr.  Agr.  Expr.  Sta.,  Bui.  91  :  29. 


84  CORN  CROPS 

each    region    has    had    some    effect    in   modifying    the 
original  type. 

SUMMARY 

60.  The  early  culture  of  corn  probably  originated  in 
the  high  plateau  region  of  southern  Mexico,  about  the 
beginning  of  the  Christian  Era.  From  here  it  spread 
north  and  south,  its  culture  being  general  throughout 
North  and  South  America  by  the  year  1000  a.d. 

The  Indians  grew  flint  and  flour  corns  chiefly,  probably 
because  of  their  keeping  and  germinating  qualities. 

Most  of  the  modern  varieties  in  general  use  in  North 
America  have  been  developed  during  the  past  century, 
though  the  principal  types  have  probably  been  in  existence 
for  many  hundred  years. 

Selection,  both  artificial  and  natural,  accounts  for  the 
origin  of  many  varieties;  while  crossing,  sometimes  in- 
tentional, but  often  accidental,  has  furnished  a  great  many 
variations  from  which  to  choose. 

References  on  early  culture  :  — 
See,  References  on  early  history  ;  p.  24. 

References  on  origin  of  varieties :  — 
Mo.  Agr.  Exp.  Sta.,  Bui.  87  :  113. 
Nebr.  Agr.  Exp.  Sta.,  Bui.  83  :  12. 
U.  S.  Dept.  Agr.  Yearbook,  1907  ;  331. 
Bowman  and  Crossly.     Corn,  p.  424. 


CHAPTER  VIII 
IMPROVEMENT  OF    VARIETIES 

Perhaps  no  other  cultivated  plant  in  America  has  been 
the  object  of  so  much  study  and  attention,  with  the  object 
of  adapting  it  to  the  various  soils,  climates,  and  needs  of 
man,  as  the  corn  plant. 

The  plant  is  large,  interesting,  lends  itself  well  to  de- 
tailed study,  and  responds  readily  to  care  or  selection. 
From  earhest  domestication  by  white  men,  there  has 
always  been  a  large  number  of  growers,  giving  time  and 
attention  to  its  improvement.  An  infinite  variety  of 
forms  has  been  developed.  Every  detail  of  the  plant  has 
been  studied  as  to  its  possible  economic  value,  in  improv- 
ing the  yield  or  quality  of  grain  or  forage.  Almost  every 
possible  theory  has  been  held  by  practical  growers  regard- 
ing the  relative  value  of  different  types  of  ear,  leaf,  stem, 
or  other  parts  of  the  plant.  Of  recent  years,  good  scien- 
tific study  has  also  been  made  at  many  of  the  experiment 
stations.  In  the  following  pages  it  is  attempted  to  sum 
up  what  is  known  to  be  of  practical  value  in  type  of  plant 
or  selection  of  methods. 

61.  Type  of  ear.  —  From  the  earliest  times  it  is  probable 
that  some  attention  has  been  given  to  the  types  of  ear 
selected  for  seed.  The  originators  of  varieties  have  usually 
had  a  well-defined  type  in  mind,  for  which  they  have 
selected.  There  is  no  evidence  that  the  type  of  ear  chosen 
has  had  a  direct  relation  to  yield,  since  equally  good 

85 


86  COEN  CROPS 

results  have  been  secured  with  very  diverse  types,  as  the 
tapering  Learning,  the  cyhndrical  Reid's  Yellow  Dent, 
the  shallow  Hickory  King,  and  the  extremely  deep- 
grained  Hackberry.  Flint  corns  and  the  small-eared, 
prolific  corns  have  also  given  excellent  results. 

Since  several  investigators  have  studied  ear  characters 
in  relation  to  yield,  all  data  verify  the  experience  of 
Hartley,  which  he  summarizes  as  follows :  ''A  careful 
tabulation  of  yields  as  compared  with  other  ear  characters, 
covering  six  years'  work  with  four  varieties,  embracing 
in  all  more  than  1000  ear-to-row  tests  of  production,  in- 
dicates that  no  visible  characters  of  apparently  good  seed 
ears  are  indicative  of  high  yielding  power."  Since  white 
men  began  corn  culture,  no  doubt  some  gain  has  been 
made  in  ability  to  yield,  but  the  fact  that  large  ears  have 
been  selected  will  account  for  this.  As  the  ear  represents 
the  producing  ability  of  a  plant,  all  other  things  being 
equal,  the  selection  of  large  ears  would  preserve  the  most 
productive  strains. 

Varieties  having  a  medium  depth  of  grain  mature 
better  and  keep  better  in  the  crib  than  very  deep-grained 
types,  and,  since  they  seem  to  yield  as  well,  they  are  to  be 
preferred. 

62.  Type  of  plant.  —  While  some  study  has  been  given 
to  the  character  of  plant,  no  definite  relationship  has  been 
proved,  which  would  justify  the  consideration  of  the  plant 
in  seed  selection,  other  than  this :  the  average  type  m  an 
acclimated  variety  will  yield  better  than  either  extreme. 
The  average  type,  however,  varies  in  different  regions. 
For  example,  on  the  west  edge  of  the  Corn  Belt,  with  a 
rainfall  of  22  to  25  inches  (central  Nebraska,  Kansas,  and 
vicinity),  the  plant  when  acclimated  is  short,  stocky, 
with  the  ear  rather  low.     To  select  here  for  tall  plants 


IMPROVEMENT  OF  VARIETIES  87 

with  the  ear  borne  high  would  not  be  in  harmony  with 
natural  conditions,  and  experience  has  shown  that  varieties 
having  these  characters  do  not  yield  so  well  as  the  native 
type.  Also,  at  the  Nebraska  station,  when  comparison 
was  made  between  broad-leaved  and  narrow-leaved 
strains  in  dry  years,  there  being  an  excess  of  sunshine  and 
limited  water  supply,  the  largest  yields  were  obtained  from 
narrow-leaved  strains.^  In  one  year,  with  excessive  rain- 
fall, broad-leaved  types  gave  larger  yields.  While  broad 
leaves  elaborate  starch,  they  also  evaporate  water  at  a 
rapid  rate ;  hence,  the  most  desirable  leaf  area  on  corn 
plants  must  be  a  balance  between  the  moisture  supply 
on  the  one  hand  and  sunshine  on  the  other. 

While  under  rather  abnormal  conditions  for  growth, 
as  a  dry  climate,  attention  must  be  given  to  the  character 
of  plant  growth,  yet  under  normal  conditions  a  wide  range 
is  permitted.  In  Illinois,  where  selection  for  height  of  ear 
was  continued  for  six  years,  there  was  no  marked  difference 
in  yield  between  the  high-ear  and  low-ear  types,  and  the 
same  was  also  true  when  angle  of  ear  was  considered. 

It  may  be  assumed  that  when  selection  is  made  for 
yield,  all  other  characters  of  the  plant  will  adjust  them- 
selves under  the  given  conditions ;  so  that  ultimately  the 
type  of  plant  giving  best  yield  under  those  conditions  will 
result.  However,  under  certain  conditions  in  the  South 
the  ears  are  borne  very  high,  and  in  the  North,  in  some 
cases,  the  ears  are  borne  very  low.  In  both  these  cases, 
for  convenience  in  harvesting,  it  would  be  well  to  select 
for  a  more  desirable  height  of  ear.  There  are  many  in- 
stances where  selection  to  modify  some  character  of  the 
plant  would  be  justified,  even  though  the  yield  was  not 
affected. 

1  Nebr.  Agr.  Exp.  Sta.,  24th  Ann.  Rpt.,  p.  158. 


88  CORN  CROPS 


SYSTEMS    OF   SELECTION 


63.  Mass  Selection  in  corn  is  the  method  of  selecting 
from  a  large  field  a  number  of  individuals  that  conform 
nearest  to  some  ideal  type.  Seed  of  these  plants  is  mixed 
together  and  planted  a  second  year  and  again  a  large 
number  of  ears  are  selected  and  mixed  for  planting  an- 
other year,  and  so  on  for  many  years. 

It  was  discovered,  however,  that  of  two  ears  much  alike 
in  appearance,  perhaps  one  might  yield  25  per  cent  to  50 
per  cent  more  than  the  other  when  used  as  seed  corn. 
The  importance  of  testing  each  ear  separately  was  at  once 
recognized. 

In  pedigree  selection  after  the  first  mother  ears  are 
selected,  a  separate  record  is  kept  on  the  performance  of 
each  ear  or  its  progeny.  For  example,  if  it  is  desired  to 
select  for  a  type  bearing  ears  low  on  the  stalk,  a  hundred 
such  ears  might  be  selected  from  a  large  field.  If  mass 
selection  is  practiced,  they  are  mixed  together  and  planted 
the  following  year  and  the  method  continued  for  several 
years.  If  pedigree  selection  is  followed,  each  ear  is  planted 
in  a  separate  row  and  a  record  made  of  the  percentage  of 
low  ears  produced  by  each  mother  ear.  Seed  ears  are 
only  saved  from  those  mother  ears  producing  a  large 
percentage  of  low  ears,  the  remainder  being  discarded. 
Perhaps  ten  mother  ears  out  of  the  first  100  will  be  found 
to  transmit  the  desired  quality.  From  the  progeny  of 
these  ten  ears,  100  ears  may  again  be  saved,  each  to  be 
planted  in  a  separate  row.  This  may  be  continued  for 
several  years,  the  performance  record  being  kept  for  every 
year.  By  keeping  a  record  on  each  family  separate  it 
will  be  possible  to  gradually  discard  those  families  not 
transmitting  the  desired  quality  and  keep  only  those  that 
are  most  desirable. 


IMPROVEMENT  OF  VARIETIES  89 

64.  Resxilts  with  mass  and  pedigree  selection.  —  With 
all  obvious  characters,  such  as  height  or  angle  of  ear,  the 
same  results  to  a  certain  degree  will  be  obtained  by  either 
method ;  but  these  results  should  be  secured  in  less  time 
by  the  pedigree  method. 

This  is  rendered  more  comprehensive  by  conceiving  a 
cornfield  to  be  a  mixture  of  types,  and  selection  as  a 


Fig.  28.  —  Selection  for  high  and  low  ears  at  the  111.  Exp.  Sta.  The  tape 
shows  height  of  ear.  The  original  selection  was  from  the  same  field 
and  had  been  continued  for  five  years  when  this  picture  was  taken. 

method  of  isolating  these  types. ^  It  is  clear  that  pedigree 
breeding  is  a  more  rapid  method  of  isolation  than  contin- 
uous selection. 

With  selection  for  yield  it  is  possible  that  no  result  would 
be  secured  with  mass  selection,  unless  there  were  some 
obvious  character  of  the  plant  closely  associated  with 
yield ;  while  on  the  other  hand,  rapid  progress  might  be 
expected  from  pedigree  cultures,  as  a  record  would  be 
kept  on  the  performance  of  each  individual. 

1  The  theory  of  isolating  pure  types  by  mass  and  pedigree  selection 
is  expounded  at  length  by  De  Vries,  in  Plant  Breeding.  Open  Court, 
Chicago. 


90 


CORN   CROPS 


65.  Mass  Selection.  —  The  result  of  mass  selection  in 
corn  is  well  illustrated  by  the  history  of  any  of  the  older 
varieties,  as  Learning,  Reid,  or  Boone  County  White. 
After  many  years'  selection,  the  breeder  succeeded  in 
producing  a  more  or  less  uniform  type. 

For  example,  the  Leaming  variety  was  originated  by 
Mr.  J.  S.  Leaming,  of  Hamilton,  Ohio  :^  "  After  fifty-six 
years'  selection,  Mr.  Leaming  produced  a  corn  having  as 
variety  characteristics  a  distinctly  tapering  ear,  fairly 
large  butts,  rather  pointed  but  well-covered  tips,  with 
kernels  of  a  deep  yellow  color,  with  very  irregular  rows." 

Hartley  produced  a  corn  with  twisted  rows  by  select- 
ing such  ears  from  the  field.  At  the  Nebraska  Agricultural 
Experiment  Station,  a  shallow-kerneled  type  of  corn  was 
fixed  by  continuous  selection  after  five  years.- 

66.  Pedigree  selection.  —  A  striking  example  has  been 
reported  from  the  Illinois  station.^     Two  sets  of  Leaming 

TABLE   Xni 

General   Averages    of    Crops    produced    in   Corn  Breed- 
ing,   FOR  High  Ears  and  for  Low  Ears 


Height 

OF  Ear 

Height  of  Plant 

Year 

High-ear  Plat 

Low-ear  Plat 

High-ear  Plat 

Low-ear  Plat 

Inches 

Inches 

Inches 

Inches 

1903   .     .     . 

56.4 

42.8 

113.9 

102.5 

1904  .     .     . 

50.3 

38.3 

106.2 

97.4 

1905   .     .     . 

63.3 

41.6 

128.4 

106.5 

1906  .     .     . 

56.6 

25.5 

116.3 

86.0 

1907   .     .     . 

72.4 

33.2 

130.4 

99.7 

1908  .     .     . 

57.3 

23.1 

114.0 

79.3 

1  Mo.  Agr.  Exp.  Sta.,  Bui.  87  :  113. 

2  Nebr.  Agr.  Exp.  Sta.,  Bui.  112  :  20. 

3  111.  Agr.  Exp.  Sta.,  Bui.  132.     1909. 


IMPROVEMENT  OF  VARIETIES 


91 


ears,  one  borne  high  on  the  stalk  and  the  other  low,  were 
selected  in  the  fall  of  1902.  Continuous  selection  was 
practiced  for  six  years,  when  a  difference  of  about  three 
feet  in  height  was  secured  in  the  average  crop,  as  shown  by 
the  table  on  previous  page. 

Results  were  also  obtained  when  selection  was  made 
to  increase  or  decrease  the  angle  of  the  ear,  the  erect-ear 
strain  and  declining-ear  strain  having  average  angles  of 
46°  and  88.50°  respectively,  after  six  years. 

67.  Selection  for  composition.  —  Composition  can  also 
be  modified  by  continuous  selection,  as  shown  by  the 
Illinois  station.  1  Ears  of  a  single  variety  were  selected  for 
high-protein,  low-protein,  high-oil,  and  low-oil  content, 
respectively.     After  ten  years'  selection,  the  high-protein 


TABLE   XIV 

Ten    Generations    of   Breeding    Corn    for    Increase  and 
Decrease  of  Protein   and  Oil 


Year 

High- 
protein 

Crop 
Per  Cent 

Low- 
protein 

Crop 
Percent 

Dif- 
fer- 
ence 

High- 
oil 
Crop 
Per  Cent 

Low- 
oil 
Crop 
Per  Cent 

Dif- 
fer- 
ence 

1896      .     .     .     . 

10.92 

10.92 

4.70 

4.70 

1897 

11.10 

10.55 

0.55 

4.73 

4.06 

0.67 

1898 

11.05 

10.55 

0.50 

5.15 

3.99 

1.16 

1899 

11.46 

9.86 

1.60 

5.64 

3.82 

1.82 

1900 

12.32 

9.34 

2.98 

6.12 

3.57 

2.55 

1901 

14.12 

10.04 

4.08 

6.09 

3.43 

2.66 

1902 

12.34 

8.22 

4.12 

6.41 

3.02 

3.39 

1903 

13.04 

8.62 

4.42 

6.50 

2.97 

3.53 

1904 

15.03 

9.27 

5.76 

6.97 

2.89 

4.08 

1905 

14.72 

8.57 

6.15 

7.29 

2.58 

4.71 

1906 

14.26 

8.64 

5.62 

7.37 

2.66 

4.71 

111.  Agr.  Exp.  Sta.,  Bui.  128.     1908. 

U.  S.  Dept.  Agr.,  Farmers'  Bui.  366 :  314. 


92 


CORN   CROPS 


selection  contained  almost  twice  as  much  protein  (14.26 
to  8.64)  as  the  low,  while  the  high-oil  selection  contained 
almost  three  times  as  much  oil  as  the 'low  (7.37  to  2.66). 
At  the  Nebraska  station,  pedigree  selection  for  yield  was 
practiced  for  five  years  in  one  case  and  two  years  in 
another,  and  an  increased  yield,  amounting  to  nine 
bushels  was  secured  in  both  cases. 


TABLE  XV 

(Class  I)   Result  of  Five  Yeaks'  Pedigree  Selection  for 
Yield.     Bushels    per   Acre 


1907 

Bushels 

1908 

Bushels 

Average 
Bushels 

Selected  strains 

Cheek  plats  (original  stock)     .     . 

82.0 
72.5 

66.0 
59.0 

74.0 
65.7 

Difference 

9.5 

7.0 

8.3 

(Class  II)   Result 

OF  Two  Years' 
Yield 

Pedig 

REE 

Sele( 

:!tion  for 

1908 

Bushels 

Selected  strains    . 
Check  plats  (origina 

L  stock)  . 

•     • 

.     .    ,. 

•       • 

68.0 
59.0 

Difference 

9.0 

References  on  type  of  ear  and  stalk :  — 
Ohio  Agr.  Exp.  Sta.,  Bui.  212.     (1909.) 
Nebr.  Agr.  Exp.  Sta.,  Bui.  No.  91,  p.  12  (1906) ;  No.  112,  p.  17 

(1909). 
Nebr.  Agr.  Exp.  Sta.,  Ann.  Rpt.  1910,  p.  154. 
Cornell    Bui.   287.     (1910.) 
111.  Bui.  132.     (1909.) 
Hartley,  C.  P.    Yearbook  U.  S.  Dept.  Agr.  1909,  pp.  309-320. 


IMPROVEMENT  OF   VARIETIES  93 

References  on  methods  of  continuous  pedigree  selection  :  — 
111.  Exp.  Sta.,  Buls.  74,  82,  100,  128. 
Conn.  Exp.  Sta.,  Buls.  152  and  168. 
Ohio  Exp.  Sta.,  Circ.  66. 
Nebr.  Exp.  Sta.,  Bui.  112. 

Directions    to    Cooperative   Corn   Breeders.      Hartley,    C.   P. 
(1910.)     Bur.  of  Plant  Industry,  Wash.,  D.C. 


CHAPTER  IX 

METHODS  OF    LAYING  OUT  A   BREEDING- 
PLAT 

While  the  principle  underlying  systematic  selection  is 
simple,  it  has  been  more  difficult  to  develop  good  methods 
for  carrying  out  the  selection  work  in  order  to  avoid  error. 
Breeding-plot  methods  have  had  a  steady  development, 
each  step  in  advance  being  intended  to  overcome  some 
source  of  error  or  to  develop  some  new  possibilities. 

In  the  reference  on  "  Methods  of  pedigree  selection," 
given  on  a  previous  page,  several  methods  for  conduct- 
ing a  breeding-plat  are  given.  The  development  of  the 
breeding-plat  plan  may  be  summarized  in  the  following 
brief  way,  beginning  about  1895  :  — 

68.  1.  Select  a  number  of  mother  ears  and  plant  in 
parallel  rows,  taking  the  yield  of  each  row  and  saving 
seed  ears  from  this  row  to  continue  in  the  same  manner. 
(See  111.  Agr.  Exp.  Sta.,  Bui.  55.) 

2.  The  above  plan  was  found  to  favor  inbreeding  and 
close  breeding,  with  danger  of  decreasing  yield.  In  order 
to  avoid  this  it  was  recommended  to  detassel  every  odd 
row,  sowing  seed  from  only  the  detasseled  rows.  Thus, 
every  odd  row  became  a  dam  while  the  even  rows  would 
be  the  sires.  By  duplicating  the  plat  and  detasseling 
the  even  rows  in  the  duplicate,  seed  could  be  saved  from 
every  mother  ear.     (111.  Agr.  Exp.  Sta.,  Bulls.  82  and  100.) 

94 


METHODS   OF  LAVING   OUT  A   BREEDING-PLAT     95 

3.  About  1904  to  1906,  Professor  Williams,  of  Ohio, 
applied  the  "  check  row  "  system  to  the  breeding-plat 
and  developed  the  "  ear  remnant  "  plan.  The  "  check 
row  "  was  a  composite  planted  for  every  sixth  row.  This 
was  for  the  purpose  of  checking  the  uniformity  of  the  land, 
as  the  breeder  might  unconsciously  select  for  a  breeding- 
plat  a  piece  of  land  more  fertile  at  one  side  than  at  the 
other. 

One  difficulty  found  with  the  ear-to-row  method  in 
practice  was  that  the  best-yielding  row  might  chance  to  be 
between  two  very  poor  yielders,  so  that  seed  ears  saved 
from  this  row  would  be  partly  crossed  with  the  poor- 
yielding  rows  on  each  side.  In  order  to  meet  this  diffi- 
culty, the  plan  was  adopted  of  planting  only  a  part  of 
each  ear,  sufficient  to  determine  the  kind  of  progeny  it 
would  develop,  and  the  remainder  of  the  ear  was  kept. 
The  next  season,  remnants  of  only  the  best  ears  would  be 
planted  in  parallel  rows  and  a  part  detasseled ;  but  with 
the  poor-yielding  rows  eliminated,  all  the  fertilization 
would  come  from  desirable  rows.  (See  Ohio  Agr.  Exp. 
Sta.,  Circ.  66  (1907);   Amer.  Breeder's  Assoc,  ///.•  110.) 


HOW  TO   CONDUCT   A   BREEDING-PLAT 

69.  As  there  is  considerable  inquiry  at  present  regarding 
methods  of  corn  breeding,  it  seems  best  at  this  time  to 
outline  a  plan  which  experience  so  far  seems  to  recommend. 

Variety  to  use.  —  Select  some  variety  that  is  well 
adapted  to  the  region  and  is  a  good  yielder.  This  is 
important,  as  one  might  spend  years  in  working  on  a  poor 
variety,  and  in  the  end  have  nothing  better  than  the  best 
variety  already  existing.  It  may  be  well  to  do  some  pre- 
liminary variety  testing. 


96  CORN   CROPS 

Selecting  the  ears.  —  If  yield  is  to  be  the  principal  object 
of  selection,  it  will  not  be  necessary  to  hold  closely  to  some 
one  type  of  ear.  In  fact,  since  we  do  not  know  definitely 
what  particular  type  of  ear  in  a  variety  may  do  best  in  a 
new  locality,  it  would  seem  wise  to  select  several  types, 
the  main  consideration  being  that  the  ears  are  sound  and 
well  matured. 

Number  of  ears  to  select  as  foundation  stock.  —  Excep- 
tional ears  are  not  common,  there  being  probably  not  more 
than  one  in  every  fifty  to  one  hundred  ears.  Therefore, 
if  one  starts  with  only  a  small  number  of  ears,  twenty- 
five  to  fifty,  he  may  not  find  a  single  exceptional  yielder 
in  the  lot.  Not  less  than  one  hundred  ears,  and  pref- 
erably two  hundred  should  be  tried  out  in  the  prelimi- 
nary trial. 

The  test  plat.  —  Great  care  should  be  exercised  in  pro- 
curing a  uniform  piece  of  land  for  the  test  plat,  as  every- 
thing depends  on  being  able  to  compare  in  an  accurate 
way  the  yields  of  the  different  ears.  The  land  should  not 
be  exceptionally  rich,  but  only  of  the  average  fertility  of 
the  region.  If  the  land  can  be  plowed  twice  —  say  fall- 
plowed,  and  then  backset  in  the  spring  —  and  disked  sev- 
eral times,  this  will  do  much  toward  equalizing  conditions. 

Size  of  plat.  —  Half  an  ear  will  plant  a  row  16  to  20 
rods  in  length.  However,  there  will  be  less  error  if  the 
rows  are  duplicated,  and  it  is  best  to  plant  two  rows  8  rods 
long  from  each  ear.  One  hundred  ears  will  make  two 
hundred  plats  8  rods  long.  This  will  take  a  piece  of  land 
32  by  11  rods  or  16  by  22  rods ;  or  two  test  plats  one-half 
this  size  on  different  parts  of  the  farm  may  be  used,  dupli- 
cating the  experiment  in  each. 

Check  plats.  —  No  matter  how  carefully  the  land  is 
selected,  it  may  lack  uniformity;    for  this  reason,  check 


METHODS   OF  LAYING   OUT  A    BEEEDING-PLAT      97 

plats  should  be  planted  with  a  uniform  lot  of  corn.  It 
has  been  found  very  satisfactory  in  practice  to  make 
every  fifth  plat  a  check.  The  simplest  way  is  to  make  a 
check  of  every  plat  that  is  a  multiple  of  5,  as  5,  10,  15,  and 
so  on. 

Planting  the  ears.  —  The  land  should  first  be  laid  off 
by  a  marker  into  checks  3  feet  8  inches  apart.  The 
planting  must  be  done  by  hand.  Carry  the  ear,  and  shell 
off  the  grains  as  needed.  It  is  best  to  plant  four  grains 
in  a  hill ;  then,  when  the  corn  is  6  inches  high,  thin  it 
down  to  two  stalks.  This  will  give  a  perfect  stand. 
Every  precaution  should  be  used  to  secure  uniform  con- 
ditions in  each  plat ;  otherwise  the  experiment  would  be 
a  waste  of  time,  as  the  results  would  not  mean  anything. 

Cultivation.  —  Ordinary  cultivation  should  be  followed, 
care  being  taken  that  none  of  the  rows  are  unduly  injured. 

Taking  notes.  —  Some  breeders  prefer  to  keep  extensive 
descriptive  notes  for  their  own  information,  but  for 
practical  results,  very  littb  note-taking  is  necessary 
other  than  accurately  to  secure  comparable  yields.  If 
the  breeder  is  selecting  for  some  particular  quality,,  such 
as  earliness,  height  of  ear,  angle  of  ear,  and  the  like,  he 
must  take  notes  on  these  points.  Also,  taking  a  set  of 
notes  on  each  individual  row  furnishes  the  very  best  train- 
ing possible  in  close  observation;  and  as  a  man  cannot 
know  too  much  about  the  corn  plant  in  order  to  be  a 
successful  breeder,  it  will  usually  pay  him  well  to  keep  as 
complete  a  record  as  possible. 

70.  Harvesting.  —  When  corn  first  ripens  it  contains 
25  to  30  per  cent  of  water,  but  it  slowly  dries  out  to  about 
15  per  cent.  In  the  breeding-plats  some  rows  ripen  and 
dry  out  sooner  than  others ;  hence,  the  weights  will  not 
be  comparable  until  all  are  equally  dry.     For  this  reason 


98  CORN   CROPS 

it  is  best  to  leave  the  breeding-plats  in  the  field  for  six 
to  eight  weeks  after  ripening,  or  until  about  December  1. 
Any  very  late-maturing  or  slow-maturing  rows  should  be 
noted  and  discarded  at  harvest,  as  a  type  that  will  not 
mature  well  is  undesirable. 

A  very  good  method  of  harvesting  the  plats  is  to  divide 
a  wagon  box  into  two  to  four  compartments.  Husk  a 
plat  into  each  compartment.  At  the  end  of  the  rows, 
have  a  platform  scale  with  a  box  large  enough  to  hold 
the  corn  from  one  plat.  Scoop  the  corn  into  this  box, 
and  as  each  plat  is  weighed,  dump  the  corn  at  the  end  of 
the  row,  leaving  the  plat  stake  with  each  pile. 

Leave  the  corn  in  these  piles  until  all  plats  are  husked, 
then  mark  the  piles  from  high-yielding  rows.  A  careful 
examination  can  now  be  made  of  these  piles  in  order  to 
note  whether  any  seem  immature,  low  in  vitality,  or  other- 
wise undesirable.  About  one-fourth  of  the  best  plats 
should  be  noted,  that  is,  20  to  25  out  of  100  piles.  From 
these,  seed  for  the  general  crop  may  be  selected  for  the 
nest  year. 

The  breeder  still  has  one-half  or  more  of  the  original 
ears  from  which  the  crop  has  grown.  It  is  from  these 
that  he  will  build  up  his  improved  strains  of  corn. 

71.  The  second  year's  work.  —  The  best  twenty  or 
twenty-five  original  ears  having  been  located,  the  rem- 
nants of  these  are  again  planted  in  separate  rows  the  second 
year.  The  reason  for  so  large  a  number  of  the  remnants 
being  again  planted  is  because  the  degree  of  error  may  be 
so  large  —  due  to  the  fact  that  one  season  may  favor  a 
certain  type  —  that  we  cannot  determine  exactly,  the  first 
year,  just  which  are  the  best  two  or  three  for  all  seasons. 
When  the  second  year's  results  are  obtained,  we  may  decide 
which  to  choose  on  the  basis  of  two  years'  record.     The 


METHODS   OF  LAYING   OUT  A   BREEDING-PLAT     99 

seed  from  the  best  two  or  three  rows  may  now  be  used 
as  foundation  stock  for  a  select  strain  of  corn.  When  the 
original  ears  are  large,  there  will  be  quite  a  remnant  left 
even  after  testing  two  years. 

72.  Continuation  of  breeding,  several  plans.  —  After 
the  second  year,  a  choice  of  several  plans  may  be 
followed :  — 

1.  Progeny  of  the  best  rows  may  be  planted  in  a  mul- 
tiplying field  for  seed.  Seed  of  this  kind  has  given  an 
increase  of  9  bushels  per  acre  (p.  92,  Class  II).  It  prob- 
ably will  not  maintain  its  increased  yield  more  than  a 
few  years  without  continued  selection. 

2.  Ears  may  be  selected  from  the  best-yielding  rows  and 
the  ear-row  selection  work  continued.  In  this  case  it 
would  be  best  to  use  some  plan  for  preventing  close  breed- 
ing. Detassel  every  alternate  ear-row  plat  having  un- 
related rows  on  each  side.  Save  seed  ears  only  from  the 
best  detasseled  plats.  This  may  be  continued  indefinitely, 
but  it  is  probable  that  new  ear-row  plats  should  be  started 
every  two  or  three  years  for  the  purpose  of  securing  new 
ears  to  be  used  as  sire  rows  in  the  breeding  block,  thus 
giving  a  new  stimulus  through  crossing.  No  work  has 
yet  been  reported  to  show  just  what  results  are  to  be 
expected. 

3.  The  original  ear  remnants  may  be  used  in  a  breed- 
ing block.  Williams  advocates  this,  using  the  best  one 
or  two  ears  for  sires  and  detasseling  the  rest.  The  ear- 
row  test  is  to  be  continued  each  year,  securing  ears  from 
various  sources,  as  the  breeding-plat,  general  crop,  or 
registered  ears  from  other  breeders.  Each  year  the  best 
remnants  will  be  saved  to  be  crossed  the  following  year 
and  passed  into  the  multiplying  plat  the  following  season. 

4.  As  the  best-yielding  ears  may  be  hybrids  of  the 


100  COBN   CROPS 

*'  elementary  strains  that  nick  well,"  plants  from  the  best 
ear  remnants  could  be  used  for  inbreeding  for  the  purpose 
of  securing  pure  strains.  There  is  more  chance  of  secur- 
ing strains  that  will  cross  well  from  these  ears  than  when 
plants  are  taken  at  random.  After  pure  strains  had  been 
secured  that  would  cross  to  advantage  as  determined  by 
experiment,  these  strains  would  be  grown  from  year  to 
year  in  isolated  fields  and  used  each  year  to  produce 
first-generation  hybrid  seed. 

SUMMARY 

73.  No  fixed  relation  has  been  found  between  type  and 
yield.  The  largest  well-matured  ears  growing  under 
normal  conditions  of  soil  and  stand  should  be  used  for 
seed.  Large  ears  with  a  medium  depth  of  grain  usually 
mature  better  than  large  ears  with  a  very  deep  grain. 

Mass  selection  and  pedigree  selection  will  ultimately 
give  similar  results  when  visible  characters  are  chosen, 
as  height  of  ear  or  shape  of  ear ;  but  with  invisible  char- 
acters, as  ability  to  yield,  results  are  not  so  sure  with 
mass  as  with  pedigree  selection,  and  at  best  they  will 
come  slowly. 

Pedigree  selection  involves  the  testing  of  each  ear  sepa- 
rately for  yield,  by  planting  a  part.  The  remnants  of 
best  ears  may  be  used  directly  as  a  foundation  stock  and 
the  progeny  may  be  continued  in  some  system  of  ear-to- 
row  selection.  The  very  highest  values  will  be  secured 
by  systematic  crossing  of  the  best  strains. 


CHAPTER  X 
RESULTS   WITH    HYBRIDIZATION 

Perhaps  no  cultivated  plant  has  yielded  so  many  inter- 
esting results  of  both  practical  and  purely  scientific  value, 
as  a  result  of  hybridization,  as  the  corn  plant.  Corn  freely 
hybridizes,  thus  offering  many  opportunities  for  the  selec- 
tion of  natural  hybrids.  The  plant  is  so  easily  manipu- 
lated in  artificial  crossing,  that  almost  any  one  may  succeed 
with  it  who  would  fail  with  other  crops.  Not  only  have 
important  results  been  secured  bearing  on  the  improve- 
ment of  yield  in  quality  of  corn,  but  also  interesting  scien- 
tific data  relating  to  the  hereditary  laws  governing  plants 
and  animals,  have  also  been  secured  with  corn. 

DEGREES   OF   RELATIONSHIP 

74.  When  pollen  of  a  maize  plant  falls  from  its  own 
tassel  on  its  own  silk,  this  is  called  "  inbreeding."  When 
pollen  from  one  variety  is  used  to  fertilize  another  variety, 
it  is  called  "  broad  breeding."  There  are  several  interme- 
diate grades  of  relationship,  which  may  be  summarized  as 
follows :  — 

1.  Inbreeding  (pollen  from  own  tassel). 

2.  Close  breeding   (pollen  from  sister  plant,   that  is, 

plant  from  the  same  ear). 

3.  Narrow  breeding  (pollen  from  plants  of   the  same 

variety) . 

101 


Fig.  29.  —  Chart  showing  possible  degrees  of  relationship  between  corn 

plants.     (See  text.) 

102 


RESULTS    WITH  HYBRIDIZATION 


103 


4.  Broad  breeding  (pollen  from  plants  of  a  different 

variety) . 

5.  Broad  breeding  (pollen  from  plants  of  a  different 

group,  as  between  flint  and  sweet  corn). 


XENIA 


75.  Cross  a  common  dent  corn  on  a  sweet  corn,  using 
pollen  from  the  former.     When  the  ear  is  mature,  instead 


4 

y> 

f-X' 

J 

f   i 

H^^^^^^r 

r 

'I 

1 

Fig.  30.  —  Method  of  covering  tassel  and  ear  for 
artificial  pollination. 

of  the  kernels  being  wrinkled  and  translucent  as  in  sweet 
corn,  a  part  of  them  will  be  smooth,  resembling  a  dent 


104  COBN  CROPS 

corn.  This  is  called  xenia,  or  "  the  immediate  effect  of 
pollen  on  the  endosperm."  The  effort  of  xenia,  however, 
is  Hmited  to  the  kernel,  there  being  no  apparent  effect  on 
the  cob  or  on  the  stalk. 

In  ordinary  hybridization,  only  the  germ  is  a  hybrid  and  the 
endosperm  surrounding  is  not  affected.  Xenia  is  accounted  for 
by  "double  fecundation."  In  ordinary  fertilization,  only  one 
of  the  two  generative  nuclei  which  are  formed  in  the  pollen  tube 
is  supposed  to  pass  into  the  embryo  sac  and  unite  with  the  egg 
cell.  In  double  fecundation  both  nuclei  enter  the  egg  sac,  one 
fusing  with  the  nucleus  of  the  egg  cell,  and  the  other  with  the 
polar  nuclei  to  form  the  embryo  sac  nucleus,  the  division  of  which 
gives  rise  to  the  endosperm.  The  endosperm  would  then  be  a 
hybrid  and  partake  of  the  dominant  characters  of  the  male 
parent. 

The  fact  that  only  a  part  of  the  kernels  show  xenia,  means 
that  double  fertilization  does  not  always  take  place.  It  is  neces- 
sary that  the  germ  cell  be  fertilized,  but  it  appears  at  present 
that  fertilization  of  the  endosperm  nucleus  is  incidental  rather 
than  necessary. 

Mendel's  laws 

76.  If  crossed  or  hybrid  kernels  of  dent  and  sweet  corn 
be  planted,  they  will  produce  ears  having  both  dent  and 
sweet  corn  kernels,  with  a  ratio  of  three  dent  corn  grains 
to  one  sweet  corn  grain.  This  is  explained  by  assuming 
that  the  germ  cells  (pollen  grains  or  ovaries)  are  either 
pure  sweet  corn  or  pure  dent  corn. 

When  a  plant  is  grown  from  a  hybrid  seed,  then,  one- 
half  the  pollen  grains  will  represent  pure  sweet  corn,  and 
one-half  pure  dent  corn,  and  the  same  with  the  ovaries. 
While  the  plants  may  be  hybrid,  the  sexual  elements  re- 
main pure.  In  the  process  of  fertilization  a  union  produc- 
ing a  hybrid  (sweet  X  dent  or  dent  X  sweet)  will  occur 
twice  as  often  as  a  pure  dent  (dent  X  dent)  or  a  pure 
sweet  (sweet  X  sweet). 


RESULTS    WITH  HYBRIDIZATION  105 

All  the  hybrid  kernels  resemble  the  dent  corn  kernels, 
so  we  apparently  have  three  dent  kernels  to  one  sweet 
kernel  on  each  self-fertilized  hybrid  ear.  If  the  seed  of 
one  of  these  hybrid  ears  be  sown,  we  apparently  harvest 
three  starchy  ears  to  one  sweet  ear,  as  follows :  — 


Germ  Cells 

Character  of  Progeny 

Starchy  x  starchy 

Starchy 

Starchy  x  sweet 

Starchy 

Sweet     X  starchy 

Starchy 

Sweet     X  sweet 

Sweet 

DOMINANT  AND   RECESSIVE    CHARACTERS 

77.  In  the  above  example,  every  hybrid  ear  has  a  starch 
grain  and  cannot  be  distinguished,  on  inspection,  from  a 
pure  starchy  type.  Starchiness  in  this  case  is  dominant 
over  the  sweet  corn  grain ;  or,  in  an  ear  that  is  a  hybrid 
of  dent  corn  and  sweet  corn,  instead  of  the  dent  and 
sweet  corn  types  blending,  thus  giving  an  intermediate, 
the  dent  completely  dominates.  In  this  case  the  sweet 
corn  is  recessive.  By  experiment  this  quality  has  been 
determined  for  many  characters  of  maize,  the  following 
being  typical  examples  :  — 

Red  colors  of  cobs,  stem,  or  husks  dominant  over  green. 
Starch  endosperm  dominant  over  sweet  endosperm. 
Yellow  endosperm  dominant  over  white  endosperm. 
Blue  aleurone  dominant  over  colorless  aleurone. 
Red  pericarp  dominant  over  colorless  pericarp. 
Podded  kernels  dominant  over  naked  kernels. 


106 


RESULTS    WITH  HYBRIDIZATION  107 


HYBRIDIZATION,    EFFECT   ON   GROWTH 

78.  Two  very  distinct  results  follow  cross-fertilization 
in  maize :  first,  certain  hereditary  characters  from  both 
parents  are  bound  up  in  the  embryo,  to  be  carried  over 
into  the  next  generation ;  second,  a  stimulus  to  vegetative 
growth  is  given,  to  be  carried  over  into  the  hybrid  genera- 
tion. The  carrying  over  of  hereditary  characters  has 
already  been  discussed  under  the  topics  "  Xenia  "  and 
"  Mendel's  Law,"  and  the  principal  discussion  here  will 
deal  with  the  second  effect  of  hybridization. 

SELF-FERTILIZATION 

79.  If  a  maize  plant  is  self-fertilized  (own  pollen  on  own 
silk),  and  this  process  is  repeated  for  two  or  three  genera- 
tions, and  selected  seeds  are  used,  there  may  gradually 
be  produced  a  "  pure  type."  That  is,  the  wide  range  of 
variation  is  decreased  each  year,  until  the  progeny  of  the 
individual,  being  self-fertiHzed,  are  all  of  one  type.  For 
example,  ShuU  self-fertilized  corn  plants  of  a  white  dent 
variety  for  five  years  and,  as  a  result,  secured  strains  that 
came  true  with  8,  10,  or  12  rows,  and  so  on  up  to  24-rowed 
ears.  The  pure  strains  differed  also  in  other  respects, 
but  all  the  plants  of  a  given  pure  strain  were  very  similar. 
At  the  Nebraska  Agricultural  Experiment  Station  ten 
very  distinct  strains  were  isolated  from  Hogue's  Yellow 
Dent,  by  inbreeding  for  three  years. 

The  inbred  strains  also  become  dwarfish  in  size,  have  a 
high  percentage  of  barren  plants,  and  sometimes  become 
entirely  sterile. 

The  decrease  in  yield  is  illustrated  by  the  following  data 
from  Shull.     Two  strains,  designated  as  A  and  B,  which 


108 


CORN  CROPS 


had  been  inbred  for  five  years  and  appeared  to  be  pure 
strains,  were  compared  with  the  original  corn.  The  table 
also  summarizes  results  with  four  strains  of  Leaming 
inbred  by  East,  and  a  combination  of  several  strains  of 
Hogue's  Dent  inbred  by  Montgomery  :  — 


TABLE  XVI 


Yield 

Experimenter 

Description  of 
Seed 

PER  Acre 

OF 

Original 
Strain 
Bushels 

Yield  per  Acre  op  Inbred 
Strain.    (Number  of  Years 
Inbred  at  Head  of  Column) 

1st 

2d 

3d 

4th 

5th 

ShulP      .     .     . 

Pure  strain  A 
Pure  strain  B 

79.4 
79.4 

14.2 
12.1 

East  2.     .     .     . 

88 

50.1 

59.9 

49.0 

51.8 

Montgomery  ^  . 

40.7 

9.9 

1  Ann.  Rpt.  Amer.  Breeders  Assoc,  Vol.  VI:  63-72.     1909. 

2  Conn.  Agr.  Exp.  Sta.,  Bui.  168.     1911. 

3  Nebr.  Agr.  Exp.  Sta.     Ann.  Rpt.  1912  :  183. 

It  is  evident  from  these  data  that  the  immediate  effect 
of  self-fertihzation  is  to  reduce  the  yield,  the  greatest 
reduction  taking  place  the  first  year. 

The  amount  of  decrease  seems  to  differ  with  varieties, 
or  even  with  strains  of  the  same  variety.  In  general, 
inbreeding  will  decrease  yield  to  about  one-half  the  first 
year.  Continuing  the  inbreeding  will  in  some  cases 
reduce  the  yield  to  one-fourth  the  original  yield,  while 
in  other  cases,  inbred  strains  become  entirely  sterile. 
Present  experiments  indicate  that  the  yield  is  reduced 
until  the  strain  becomes  a  "  pure  strain,"  after  which 
inbreeding  has  no  further  effect  in  decreasing  yield. 

Very  often  abnormal  types  appear  in  inbred  strains. 


RESULTS    WITH  HYBRIDIZATION 


109 


Fig.  32.  —  The  effect  of  three  degrees  of  relationship  in  crossing  is  here 
illustrated.  Nos.  3  and  4  are  pure  strains  inbred  for  three  years.  No. 
2  from  a  close  fertilized  seed-stock,  the  plants  each  year  fertilized  from 
sister  plants  from  the  same  ear.  No.  1  is  from  a  seed-stock,  cross  fer- 
tilized for  three  years. 


PURE   STRAINS,    OR   BIOTYPES 

80.  Doctor  Shull  first  presented  the  idea  that  a  corn- 
field is  to  be  considered  more  or  less  a  mixture  of  pure  types 
(biotypes)  and  that  most  of  the  plants  in  a  field  are  more 
or  less  complex  hybrids.  By  inbreeding,  some  of  the 
original  pure  types  might  be  isolated.  In  other  words,  a 
cornfield  is  a  complex  mixture  of  types,  and  inbreeding 
gives  much  the  same  result  as  does  a  chemical  analysis  with 
a  complex  compound — resolves  it  into  its  original  elements. 


Fig.  33.  —  Pure  types  such  as  may  be  originated  from  a  single  variety  or  ear 
of  corn  by  inbreeding.    They  are  reduced  in  size,  but  each  type  comes  true. 

110 


BESULTS    WITH  HYBRIDIZATION 


111 


CROSSING   BIOTYPES 

81.  However,  these  ''elemental  strains"  are  low  in  yield, 
but  are  stimulated  to  yield  by  hybridizing.  The  effect 
of  hybridizing  as  a  stimulus  is  shown  in  the  following 
table :  — 

TABLE   XVII 


Experimenter 

Description  of 
Seed 

Yield  per 
Acre  of 

Pure 
Strains 
Bushels 

First- year  Yield 

per  Acre  of 

Cross  of  Pure 

Strains 

Bushels 

Second- year 
Yield  per  Acre 
of  Progeny  from 

Hybrid  Seed 
Bushels 

Shull      .     . 
East       .     . 

J  Pure  type  A 
[Pure  type  B 

Learning 
No.  12 

Learning 
I     No.  9 

14.2. 
12.1] 

35.4 

23.3  J 

79.8 
110.2 

69.5 

98.4 

The  corn  is  at  once  restored  to  full  vigor  by  hybridizing. 
The  yield  appears  to  decrease  somewhat  the  second 
year,  probably  because  a  certain  percentage  of  the  plants 
have  returned  to  a  pure-type  (homozygous)  state. 

Under  natural  conditions  there  is  a  certain  percentage 
of  both  inbreeding  and  close  breeding.  This  has  led  to 
the  suggestion  that  means  should  be  used  to  insure  that 
all  seed  used  is  first-generation  hybrid.  This  can  be 
accomplished  by  alternating  rows  of  pure  strains  and 
detasseling  every  alternate  row,  saving  seed  from  the 
detasseled  rows. 

CROSSING   VARIETIES 

82.  Several  investigations  have  shown  an  increase  from 
the  use  of  first-generation  hybrid  seed,  when  two  varieties 
have  been  crossed.     The  following  table,  summarized  from 


112 


COBN  CROPS 


Morrow  and  Gardner's  experiments  in  1892  at  the  Illi- 
nois Agricultural  Experiment  Station,  illustrates  :  ^  — 

TABLE  XVIII 


Variety 


Burr's  White    .     .     . 
Cranberry   .... 

Average     .     .     . 

Cross    .... 

Burr's  White    .     .     . 
Helm's  Improved 

Average    .     .     . 

Cross    .... 

Leaming      .... 
Golden  Beauty     .     . 

Average     .     .     . 

Cross    .... 

Champion  White  Pearl 
Leaming      .... 

Average     . 

Cross    .... 

Burr's  White    .     .     . 
Edmonds     .... 

Average     .     .     . 

Cross    .... 


Bushels  op 
Air-dry  Corn 


64.2 
61.6 
62.9 
67.1 

64.2 
79.2 
71.7 
73.1 

73.6 
65.1 
69.3 

86.2 

60.6 
73.6 
67.1 

76.2 

64.2 

58.4 
61.3 

78.5 


The  average  yield  of  hybrids  in  the  five  tests  was  9.7 
bushels  above  the  average  of  the  parents  and  4.5  bushels 
above  the  average  of  the  highest  parents.  It  is  also 
shown,  by  this  and  other  data,  that  certain  crosses  give 


111.  Agr.  Exp.  Sta.,  Bui.  25.     1902. 


RESULTS    WITH  HYBRIDIZATION 


113 


greater  increases  than  do  others.  Hartley  has  found  that, 
while  certain  crosses  give  an  increase,  others  give  a 
decrease,  and  in  some  cases  the  cross  is  almost  sterile. 
Probably  those  varieties  that  have  been  longest  selected 


Fig.  34. 


A  breeding  plat  where  many  tassels  and  ears  are  covered  with 
paper  bags,  for  artificial  pollination. 


as  to  type,  and  therefore  are  the  nearest  to  a  pure  (homo- 
zygous) state,  will  respond  most  readily  to  crossing. 

83.  Shull  has  found  that  when  a  variety  has  been 
resolved,  by  inbreeding,  into  pure  strains,  certain  of  these 
pure  strains  when  crossed  give  yields  superior  to  the  yield 
of  the  original  corn,  while  other  combinations  give  poor 
yields.  He  suggests  that  the  maximum  yields  will  be 
secured  by  first  reducing  a  variety  to  its  elemental  strains, 
and  then  producing  hybrid  seed  each  year  from  only 


114  CORN  CROPS 

those  strains  that  give  maximum  results.  This  would 
necessitate  maintaining  the  pure  strains  each  in  a  separate 
field  from  year  to  year,  and  having  another  seed  field  where 


Fig.  35.  —  Pure  types  as  developed  by  inbreeding.     No.   11   produces 
many  tillers,  and  was  reddish  in  color.     No.  12  was  free  from  tillers. 


they  would  be  planted  in  alternate  rows.  One  strain 
would  be  detasseled  in  this  seed  patch,  thus  giving  each 
year  a  stock  of  hybrid  seed. 


RESULTS    WITH  HYBRIDIZATION  115 

ISOLATING    HIGH-YIELDING    BIOTYPES 

84.  Evidence  at  present  indicates  that  high-yielding 
ears,  found  by  the  ear-row  method  of  testing,  are  in  many 
cases  natural  hybrids  of  high-yielding  biotypes.  Thus 
by  securing  high-yielding  ear  remnants  as  foundation 
stock,  they  might  be  inbred  until  pure  types  were  ob- 
tained. There  is  greater  probability  of  securing  biotypes 
that  would  combine  to  advantage  from  this  stock  than  if 
a  chance  stock  were  used  as  a  beginning. 

SUMMARY 

85.  Fertilization  is  the  result  of  the  union  of  the  con- 
tents of  a  pollen  grain  with  the  egg  cell  of  an  ovary. 
Xenia  is  the  immediate  effect  of  pollen  in  changing  the 
character  of  the  maize  grain. 

Mendel's  law  refers  to  the  phenomenon  of  transmitting 
characters  in  toto,  without  blending,  as  in  the  case  of 
dent  and  sweet  corn  when  crossed. 

Hybridization  usually  gives  a  decided  stimulus  to  growth, 
while  self-fertilization  has  the  opposite  effect.  Continuous 
self-fertilization  may  reduce  yield  to  one-fourth  or  less 
of  the  original  yield,  but  the  yield  is  fully  restored  in  the 
first  generation  hybrids.  A  field  of  corn  appears  to  be  a 
miscellaneous  mixture  of  biotypes,  naturally  not  very 
productive,  but  stimulated  to  the  highest  degree  of  pro- 
ductivity by  hybridizing.  Certain  biotypes  hybridize 
to  better  advantage  than  do  others. 

References  on  xenia  :  — 
Webber,  H.  J.     (1900.)     Xenia.     U.  S.  Dept.  Agr.,  Div.  Veg. 

Physiol,  and  Path.,  Bui.  22. 
GuiGNARD,  L.     (1901.)     La  Double  Fecundation  dans  le  Mais. 

Journ.  Bot.     [Paris],  15  :  1-14.     No.  2. 


116  CORN   CROPS 

References  on  inheritance  in  maize :  — 
CoRRENs,  C.    (1901.)    Bastarde  zwischen  Maisrassen  mit  Beson- 

derer  Berucksichtigung  der  Xenien.     Bibliotheca  Bot.,  55: 

1-161. 
Lock,  R.  H.     (1906.)     Studies  in  Plant  Breeding  in  the  Tropics, 

111.     Ann.  Roy.  Bot.  Gard.     Peradeniya,  3:  95-184. 
East,  E.  M.     A  Note  Concerning  Inheritance  in  Sweet  Corn. 

Science,  N.  S.  29 :  465-467. 
1911.     Inheritance  in  Maize.     Conn.  Agr.  Exp.  Sta.,  Bui.  167. 
Emmerson,  R.  a.    (1911.)     Genetic  Correlations  and  Spurious 

Allelomorphism   in   Maize.     24th   Ann.    Rpt.    Nebr.    Agr. 

Exp.  Sta. 

References  on  crossing  varieties  :  — 

Collins,  G.  W.  (1909.)  The  Importance  of  Broad  Breeding  in 
Corn.     U.  S.  Dept.  Agr.,  Bur.  Plant  Indus.,  Bui.  141. 

(1910.)  The  Value  of  First-Generation  Hybrids  in  Corn.  U.  S. 
Dept.  Agr.,  Bur.  Plant  Indus.,  Bui.  191. 

Increased  Yields  of  Corn  from  Hybrid  Seed.  U.  S.  Dept.  Agr. 
Yearbook  1910  :  319-328. 

Morrow,  G.  E.,  and  Gardner,  F.  D.  (1892.)  Field  Experi- 
ments with  Corn.     111.  Agr.  Exp.  Sta.,  Bui.  25:  173-203. 

Kellerman,  W.  a.,  and  Swingle,  W.  T.  Ann.  Rpt.  Kans. 
Agr.  Exp.  Sta.,  No.  1  :  316-337,  1889;  No.  2:  288-355, 
1890 ;  and  Kans.  Agr.  Exp.  Sta.,  Bui.  27  :  139-158.     (1891.) 

East,  E.  M.     Conn.  Agr.  Exp.  Sta.,  Bui.  167.     1911. 

Hartley,  C.  P.,  and  associates.  Cross-breeding  Corn.  U.  S. 
Dept.  Agr.,  Bur.  Plant  Indus.,  Bui.  218. 


CHAPTER  XI 
ACCLIMATION   AND    YIELD 

A  BOTANICAL  survey  of  the  United  States  shows  large, 
well-defined  regions,  each  with  a  characteristic  native 
flora. 

86.  Considering  the  great  length  of  time  that  native 
vegetation  has  had  in  which  to  adjust  itself,  these  various 


Fig.  36.  —  Prairie  vegetation  in  the  "  short  grass  "  region.    The  natural 
vegetation  indicates  a  very  great  difference  in  natural  climate. 

regions  must  indicate  different  environmental  conditions, 
or  else  we  should  have  a  homogenous  native  vegetation 
throughout  the  country.  Those  regions  covered  with  a 
forest  vegetation  must  differ  in  environment  (soil  or  cli- 
mate) from  a  prairie  region.  There  are  various  kinds  of 
forest  regions,  as  evergreen  and  deciduous ;  while  in  the 

117 


118 


CORN  CROPS 


prairies  we  have,  along  the  Missouri  River,  a  tall  vegeta- 
tion of  grass  and  other  plants,  waist-high  to  a  man,  in 


Fig.  37.  —  Prairie  vegetation  in  humid  region.  Compare  with  Fig.  36. 
There  must  be  quite  a  marked  difference  in  the  types  of  corn  adapted 
to  these  two  regions. 

marked  contrast  to  the  ''  short  grass  "  country  three  hun- 
dred miles  westward. 

Even  within  a  State  distinct  floral  zones  can  often  be 
identified,  as  in  Nebraska,  for  example,  where  six  zones 
are  recognized,  each  with  a  characteristic  vegetation. 


EFFECT  OF  ENVIRONMENT  ON  THE  CORN  PLANT 

87.  It  has  long  been  observed  that  each  region  would 
have  a  distinct  type  of  corn  plant.  In  northern  regions 
the  plant  is  leafy  with  the  ear  borne  very  low;  in  dry 
regions  the  plant  is  stocky,  with  a  high  proportion  of  ear 
and  often  with  scant  leaf;   while  in  southern  regions  the 


ACCLIMATION  AND    YIELD 


119 


plants    are    tall    and    have    a   low    proportion  of  ear  to 
stalk. 


EFFECT    OF    PREVIOUS    ENVIRONMENT   ON    YIELD 

88.  The  marked  effect  of  a  change  in  environment  on 
yield  of  grain  has  often  been  noted,  the  change  usually 
decreasing  the  yield  at  first.  At  the  Arkansas  station/ 
233  samples  of  corn  were  collected  from  various  States 
and  grown  in  comparison  for  two  years. 

In  155  trials  with  seven  varieties,  the  highest  yield  was 

secured   with   seed   grown   between  the   thirty-fifth   and 

thirty-eighth    parallels    of    latitude,    rather    than    either 

north  or  south  of  this  region,  this  being  the  latitude  of  the 

Arkansas  station, 

TABLE   XIX 

Table  showing  the  Yield  of  Corn  from  Seed  of  Differ- 
ent Sources  at  the  Arkansas  Agricultural  Experi- 
ment Station 


Names  of  Varieties 

Num- 
ber OF 

Tests 

Seed  grown 

North  of  38th 

Parallel  of 

Latitude 

Seed  grown 
between  35th 

and  38th 
Parallels  of 

Latitude 

Seed  grown 

South  of  35th 

Parallel  of 

Latitude 

Average  for  2 
Years 

Average  for  2 
Years 

Average  for  2 
Years 

Learning    . 
Golden  Beauty  . 
Hickory  King     . 
Golden  Dent 
Champion  White 
Pearl      .     .     . 
Early  Mastodon 
White  Dent   .     . 

21 
20 
23 

26 

11 
16 

38 

20.98 
32.81 
24.855 
21.52 

22.62 
33.54 
24.175 

26.20 
45.775 
31.81 
25.00 

32.00 
33.75 
34.695 

17.20 
50.475 
29.10 
25.30 

30.10 
33.45 
34.775 

Average  Total 

155 

25.785 

32.47 

31.485 

1  Newman,  C.  L.     (1899.)     Ark.  Agr.  Exp.  Sta.,  Bui.  59. 


120 


CORN  CROPS 


At  the  Nebraska  Agricultural  Experiment  Station  six 
leading  varieties  of  corn  were  compared  for  two  and  three 
years,  the  seed  in  one  case  being  native-grown  and  in  the 
other  from  Iowa  or  Illinois.     Results  were  as  follows:  — 


TABLE  XX 

Table  showing  Yield  of  Corn  from  Acclimated  Seed  and 
Seed  from  Other  Regions,  at  the  Nebraska  Agricultu- 
ral Experiment  Station 


Name  and  Places  of  Origin 

1903 

1904 

1905 

Average 

Differ- 
ence 

^.,          .       [  Nebraska 
Silvermine  {  j^j.^^.^ 

Learning  jjj^.^^.^    .     .     .     . 

Snowflake  f  Nebraska  .     .     . 

White     1  Iowa     .... 
Boone  County  |  Nebraska    . 

White             1  Illinois    . 
Early  Yellow  f  Nebraska 

Rose             [  Iowa    . 
Reid's  Yellow  f  Nebraska      . 

Dent              [  Illinois     . 

73.7 

68.7 

68.1 
62.1 

70.0 
65.1 
95.2 
76.6 

84.8 
72.8 
76.2 
68.9 
67.9 
76.9 
83.8 
82.8 

76.1 
63.4 
69.8 
72.3 
74.5 
67.1 

75.1 
63.5 
64.2 
60.8 

73.0 
64.2 
82.5 
74.4 
77.7 
69.5 
76.2 
68.9 
70.3 
67.5 
73.7 
71.8 

8.8 
8.1 
8.2 
7.3 
2.8 
1.9 

Average 

6.2 

In  every  case  the  native  seed  gave  best  results. 

In  another  experiment  conducted  with  farmers  in  western 
Nebraska,  it  was  found  that  native-grown  seed  gave  better 
results  than  seed  grown  in  eastern  Nebraska.^  Rainfall  in 
the  western  part  of  the  State  is  very  low,  averaging  about 
18  inches  annually,  while  the  rainfall  is  about  30  inches 
in  eastern  Nebraska.  To  succeed  in  the  West  corn  must 
be  adapted  to  drought  resistance. 


Nebr.  Agr.  Exp.  Sta.,  Bui.  126.     1912. 


ACCLIMATION  AND    YIELD 


121 


TABLE   XXI 

Table  showing  Comparative  Yield  of  Native-  and  Im- 
ported-seed  corn  in  western  nebraska  in  bushels 
PER  Acre 


Year 

Varieties  not 

Native  (mostly 

FROM  Eastern 

Nebraska) 

Native  Varieties 

Difference 

1908  .... 

1909  .... 

24.1 
20.9 

30.5 
25.4 

6.4 
4.5 

Average    .     .     . 

22.5 

27.9 

5.4 

ADAPTATION    OF   THE    SOIL 

89.  The  climatic  and  soil  requirements  of  corn  have  been 
stated  in  Section  II.  The  climate  cannot  be  controlled 
or  modified  in  a  marked  degree,  hence  corn  production 
is  limited  by  climate  to  those  regions  where  the  natural 
rainfall,  temperature,  and  like  conditions  are  favorable  to  a 
profitable  production. 

The  soil,  however^  is  subject  to  treatment,  and  almost 
every  soil  can  be  brought  to  a  high  degree  of  productive- 
ness by  proper  management.  The  subject  of  soil  manage- 
ment is  so  fully  treated  in  special  texts  on  this  topic,  that 
it  is  not  necessary  to  take  up  the  matter  in  detail  here. 

From  a  study  of  corn  soils  as  classified  according  to 
productiveness,  it  is  apparent  that  a  large  proportion  of 
the  soil  likely  to  be  cultivated  in  corn  may  be  grouped  in 
two  classes :  first,  soils  that  were  once  productive  but 
are  now  more  or  less  deplete  by  50  to  200  years  cropping  ; 
and  second,  soils  that  never  were  productive.  In  both 
cases  the  important  factors  to  be  modified  can  be  grouped 
under  three  general  heads,  as  follows  :  (1)  organic  matter, 
(2)  mineral  matter,  (3)  water. 


CHAPTER  XII 

CROPPING  SYSTEM  IN  RELATION  TO  MAIN- 
TAINING   THE    YIELD   OF   CORN 

The  discussion  so  far,  on  the  adaptation  of  soil  for  corn 
growing,  brings  out  the  fact  that  the  constant  growing 
of  corn  involves  the  development  of  a  cropping  system 
by  which,  w^ith  the  least  cost,  the  organic  matter  can  be 
maintained  and  the  most  profitable  use  made  of  any 
fertilizing  material  that  it  may  be  necessary  to  add. 

90.  Cropping  systems  in  the  United  States  undergo  evo- 
lution from  the  time  when  new  land  is  opened  up  to  the 
time  when  it  reaches  a  permanent  agricultural  basis. 

When  new  land  is  first  brought  under  cultivation,  grain 
farming  is  the  general  custom.  Often  a  single  crop  is 
cultivated,  as  wheat  in  the  Northwest.  In  a  few  years 
the  single  crop  becomes  unprofitable,  due  to  the  coming  of 
insect  pests  or  plant  diseases,  or  to  the  decreasing  avail- 
ability of  some  mineral  element  in  the  soil.  Then  cul- 
tivated crops  are  introduced  to  alternate  with  the  small 
grain. 

In  many  regions  of  the  Corn  Belt,  corn  was  continu- 
ously raised  until  it  became  necessary  to  introduce  small 
grain  culture.  After  a  time,  however,  the  continuous 
rotation  of  grain  crops  alone  no  longer  gave  paying  crops. 
In  general,  this  appears  to  be  due  to  :  — 

1.  Exhaustion   of    actual   organic    matter   resulting  in 
(a)  Decrease    in     availability    of     some    necessary 

element  as  phosphorus,  or 
(6)  Poor  physical  condition  of  the  soil. 
122 


CROPPING   SYSTEM  128 

2.  Exhaustion  of  some  necessary  element,  usually  lime, 
nitrogen,  phosphorus,  or  potassium. 

RESTORING   PRODUCTION 

91.  When  low  production  is  due  to  the  exhaustion  of 
organic  matter,  then  any  cheap  system  of  restoring  that 
matter,  as  plowing  under  a  green  manure  crop,  will  usually 
restore  production  in  a  measure.  One  effect  of  this  de- 
caying organic  matter  is  the  reaction  on  the  minerals  of  the 
soil,  thus  increasing  solubility,  and  restoring  the  physical 
condition.  The  physical  effect  is  to  make  the  soil  more 
loamy  in  character  by  increasing  granulation  of  clay,  on 
the  one  hand,  and  on  the  other  hand,  in  the  case  of  sandy 
soils,  binding  the  particles  together.  In  this  case  no  new 
supply  of  plant  food  is  added  to  the  soil,  as  the  organic 
matter  is  grown  on  the  land  and  only  adds  to  the  soil  the 
carbon  compounds  taken  from  the  air.  Adding  organic 
matter  from  an  outside  source,  in  addition  to  the  above, 
also  adds  its  own  supply  of  elements. 

When  a  certain  element  has  been  exhausted  from  the 
soil,  that  element  may  be  added. 

Nitrogen  may  be  added  in  three  ways  :  (1)  by  growing 
leguminous  crops ;  (2)  by  adding  organic  matter  from  an 
outside  source ;   (3)  by  adding  nitrogen  salts. 

Phosphorus,  potassium,  and  lime  can  be  restored  in  two 
ways :  (1)  by  adding  organic  matter  from  an  outside 
source ;  (2)  by  adding  salts  of  phosphorus,  potassium,  or 
lime. 

Aside  from  a  proper  system  of  drainage  where  needed, 
the  whole  problem  of  devising  a  cropping  system,  includ- 
ing the  application  of  fertilizers  for  maintenance  or  in- 
crease of  production,  is  involved  in  the  above  statements. 


124 


COBN  CROPS 


Cropping  systems  may  then  be  classed  as :  — 

(1)  Those  that  decrease  productivity. 

(2)  Those  that  maintain  productivity. 

(3)  Those  that  increase  productivity  (or  in  most  cases 
merely  restore  it). 

Experiments  demonstrating  the  above  cases  have  been 
made  in  a  number  of  States  where  corn  was  used  as  one  of 
the  crops  in  the  system. 

MAINTAINING   PRODUCTION 

92.  Results  are  reported  from  the  lUinois  station,^  where 
corn  has  been  grown  in  three  systems  of  cropping,  for  13 
years  in  one  case  and  for  29  years  in  the  other. 

TABLE  XXII 

Illinois  Corn  Yields  where  Three   Systems  of    Cropping 
ARE  Compared.    Average  Yield  for  Last  Three  Years 


Crop  Years 

CropSystem 

13- YEAR 

Experiments 
Bushels 

29-YEAR 
ExPERIME>fTS 

Bushels 

1905-6-7       .     . 
1903-5-7       .     . 
1901-4-7       .     . 

Corn  every  year 
Corn  and  oats 
Corn,  oats,  clover 

35 
62 
66 

27 
46 

58 

The  land  on  which  these  experiments  were  conducted 
originally  produced  more  than  70  bushels  per  acre.  There 
has  been  some  decrease  in  yield  in  all  cases,  but  less  de- 
crease where  rotation  was  practiced.  Yield  cannot  be 
maintained  by  rotation  alone  where  the  crops  are  removed. 

In  a  second  series  of  plots  a  corn-oats-clover  rotation  was 
practiced,  where  all  was  returned  to  the  land  except  the 
grain  and  clover  seed  harvested.     In  one  case,  the  straw, 

1  111.  Agr.  Exp.  Sta.,  Bui.  125  :  324.     1908. 


CROPPING   SYSTEM 


125 


cornstalks,  and  clover  were  all  plowed  under,  and  this 
system  was  designated  as  ''  grain  farming  "  since  no  live 
stock  to  produce  manure  was  needed. 


Fig.  38.  —  Good  land,  continuously  cropped  with  grain,  until  it  is  in  an 
unproductive  state. 

In  a  second  series,  designated  '' live-stock  farming,"  the 
crops  have  been  removed  but  equivalent  manure  returned. 


Crop  Years 

Special  Treatment 

Grain 
Farming 
Legumes  ^ 

Live-stock 
Farming 
Manure  ^ 

Bushels 

Bushels 

1905-6-7       .     . 

None 

69 

81 

1905-6-7       .     . 

Lime 

72 

85 

1905-6-7       .     . 

Lime,  phosphorus 

90 

93 

1905-6-7       .     . 

Lime,     phosphorus, 

potassium 

94 

96 

1  Legume  catch-crops  and  crop  residues. 

2  Manure  applied  in  proportion  to  previous  crop  yields. 

Growing  legumes  and  returning  all  residues  has  main- 
tained yield,  and  when  in  the  form  of  manure  has  increased 


126 


CORN   CROPS 


yield.  When  additional  minerals  have  been  added,  the 
crop  production  has  been  actually  increased  about  20 
per  cent. 

At  the  Indiana  station  ^  five  cropping  systems  have  been 
compared  for  20  years,  with  and  without  commercial 
fertihzers.  Without  giving  details,  the  following  table 
shows  clearly  enough  the  comparative  effect  of  different 
cropping  systems  on  the  maintenance  of  production. 

TABLE  XXIII 

Indiana  Experiments,  comparing  Corn  Yields  at  Begin- 
ning AND  End  of  Twenty-year  Period  in  Different 
Rotations 


Cropping  Systems  and  Yields  in  Bushels  per  Acre 

Treatment 

I 

Continuous 
Corn 

II 

Corn  and 
Wheat 

III 

Corn,  Oats, 
Wheat- 
Clover 

IV 

Corn,  Oats, 
Wheat, 
Clover- 
Grass 

V 

Corn-roots, 
Oats, 
Wheat, 
Clover- 
Grass 

Yields  in  1889  when  the  Experiments  were  Begun 

Unfertilized  . 
Fertilized      . 

61.1 
62.1 

50.0 
49.3 

54.6 

54.8 

54.2 
56.4 

58.4 

58.1 

Yields  in  1909  after  20  Years'  Cropping 

Unfertilized . 
Fertilized 

26.0 
39.9 

25.4 
47.3 

47.8 
59.1 

35.5 
65.5 

61.1 
73.1 

Unfertilized 
Fertilized 


Difference  between  1889  and  1909  Yields,  showing 
Effects  of  Rotations 


35.1 
22.2 


-24.6 
-2.0 


-6.8 
+  4.3 


-  18.7 
+  9.1 


+  2.7 
+  15.0 


Ind.  Agr.  Exp.  Sta.,  Circ.  25,     19U. 


CROPPING   SYSTEM 


127 


The  Indiana  results  confirm  the  Illinois  experiments, 
showing  :  (a)  a  rapid  decrease  for  continuous  grain  culture ; 
(b)  a  maintenance  of  yield  for  longer  period  when  a 
rotation  including  legumes  and  grass  is  included ;    (c)  an 


Fig.  39.  —  Compare  with  Fig.  38.     The  same  kind  of  land  near  by,  but 
properly  managed  to  maintain  productivity.     (Minn.  Exp.  Sta.) 

actual  increase  in  productivity  when  fertilizer  is  added. 
However,  fertilizer  did  not  maintain  yield  in  a  grain  rotation. 


ROTATIONS    FOR    CORN    GROWING 

93.  The  above  tables  suggest  the  type  of  rotations 
and  fertilizer  treatment  for  the  Corn  Belt.  Other  stations 
have  suggested  rotations  including  corn,  as  follows :  ^  — 

"  A  rotation  for  dairy  farms  recommended  by  the  New 
Jersey  station  consists  of  (1)  field  corn,  seed  to  crimson 
clover  in  July  or  August ;    (2)  crimson  clover  followed  by 

1  U.  S.  Dept.  Agr.,  Farmers'  Bui.  1U--  H- 


128  CORN  CROPS 

fodder  corn,  land  seeded  to  winter  rye ;  (3)  rye  fodder, 
followed  by  oats  and  peas,  seeded  to  red  clover  and 
timothy ;  (4)  hay.  [Crimson  clover  is  not  hardy  north  of 
New  Jersey.  —  Author.] 

"  A  three-year  rotation  for  the  South,  recommended 
by  the  Louisiana  station,  is  (1)  corn ;  (2)  oats,  followed  by 
cowpeas;  and  (3)  cotton. 

''  At  the  Delaware  station  a  good  rotation  for  a  poor 
soil  in  bad  condition  was  (1)  sweet  corn,  crimson  clover ; 
(2)  cowpeas,  winter  oats ;  and  (3)  red  clover.  A  fertilizer 
was  applied.  The  results  reported  indicate  that  it  is 
better  to  have  crops  growing  continuously  up  in  the  land, 
than  to  have  it  lying  idle  during  a  part  of  the  growing 
season." 

Each  farmer  must  work  out  the  rotation  system  best 
adapted  to  his  own  situation,  but  the  general  lines  to  fol- 
low are  indicated  in  the  foregoing  discussion^ 


CHAPTER  XIII 
ORGANIC  MATTER  FOR   CORN  LAND 

Organic  matter  has  several  important  functions  in  the 
soil :  (1)  As  a  direct  source  of  food  supply.  Decaying 
vegetable  and  animal  matter  contains  all  the  essential  food 
elements  of  plants.  (2)  As  a  means  of  freeing  unavailable 
plant  food  elements  in  the  soil.  The  organic  acids  given 
off  by  decaying  organic  matter  act  directly  on  the  elements 
of  the  soil,  in  bringing  them  into  solution.  (3)  The  phys- 
ical condition  of  the  soil  is  affected  in  a  remarkable  degree 
by  the  presence  of  even  a  small  percentage  of  organic 
matter.  Note  the  effect  on  a  clay  soil  when  a  few  loads 
of  manure  are  applied  to  an  acre  of  land.  The  organic 
matter  improves  the  granulation  and  increases  the  water- 
holding  capacity  to  some  extent.  Aeration  is  also  im- 
proved. (4)  A  very  important  effect  is  to  improve  the 
soil  as  a  medium  for  the  growth  of  soil  bacteria  and  fungi, 
which  in  turn  become  a  source  of  organic  matter  to  the 
soil.  (5)  Nitrogen-fixing  bacteria  are  favored  by  abundant 
organic  matter,  if  sufficient  lime  be  present. 

Considering  the  fact  that  corn,  in  common  with  all 
cereals,  must  be  grown  without  the  extensive  use  of  com- 
mercial forms  of  fertilizer,  maintaining  the  supply  of  organic 
matter  in  the  soil  becomes  the  most  important  single  consid- 
eration in  extensive  corn-growing  regions, 

94.  Good  corn  soils  are  rich  in  organic  matter.  Two  of 
the  best  corn  soils  in  the  Central  States  are  Miami  black 
K  129 


130 


CORN  CROPS 


clay  loam  and  Wabash  silt  loam,  the  organic  matter  of 
which,  according  to  Lyon  and  Fippin,^  is  as  follows :  — 


Miami  black  clay  loam 
Av.  12  samples     . 

Wabash  silt  loam 

Av.  11  samples     . 


Soil  0-7  Inches 

Per  Cent 
Organic  Matter 


5.9 
3.3 


Subsoil  7-40  Inches 

Per  Cent 

Organic  Matter 


2.50 
1.30 


Of  all  the  cereals  corn  is  the  best  crop  to  grow  first, 
after  a  heavy  application  of  manure  or  the  plowing  under 
of  organic  matter,  as  a  clover  sod  or  green  manure  crop. 
It  is  well  adapted  to  utilize  the  rather  large  store  of 
nitrogen  hkely  to  become  available  at  such  time.  Be- 
cause corn  does  well  following  the  plowing  under  of  coarse 
organic  matter,  it  is  sometimes  called  a  "  coarse  feeder  "  ; 
while  wheat,  requiring  a  more  advanced  stage  of  decom- 
position, is  termed  a  "  delicate  feeder." 

FARMYARD    MANURE    FOR    CORN 

95.  It  has  been  demonstrated  that  lime,  under  certain 
conditions,  applied  to  the  land  gave  profitable  increases ; 
in  certain  other  cases  commercial  fertilizers  have  been 
profitable ;  but  farmyard  manure,  wherever  used,  has 
usually  given  profitable  returns.  It  appears  at  present, 
however,  that  for  a  large  share  of  the  corn-growing  area 
farmers  are  not  justified  in  keeping  sufficient  live  stock 
in  their  farming  systems  to  depend  on  manure  as  the 
principal  means  of  maintaining  production.     It  must  be 


Lyon  and  Fippin.     Soils,  p.  125. 


ORGANIC  MATTER    FOR    CORN    LAND 


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132  CORN  CROPS 

supplemented  by  plowing  under  organic  matter,  especially 
green  crops,  containing  enough  legume  crops  to  maintain 
the  nitrogen  supply. 

Perhaps  the  best  comparative  idea  of  the  value  of  farm- 
yard manure  and  fertilizers  can  be  obtained  by  examining 
certain  data  secured  at  the  Pennsylvania  station  in  a 
twenty-five-year  test,  two  experiments  at  the  Ohio  station 

—  one  for  sixteen  years  and  the  other  for  thirteen  years 

—  a  nine-year  test  at  the  Indiana  station,  a  thirteen-year 
record  at  the  Illinois  station,  and  a  single  corn  crop  after 
timothy  at  the  Cornell  station. 

The  foregoing  table  is  a  summary  of  the  data  secured  at 
the  Pennsylvania  and  Ohio  stations.  These  are  the  best 
continuous  records  that  we  have  in  the  older  portion  of 
the  United  States,  where  the  use  of  manure  and  fertilizers 
is  now  becoming  a  matter  of  importance. 

The  summary  shows  that  land  yielding,  under  a  good 
rotation,  an  average  of  35.4  bushels  of  corn  per  acre  has 
been  maintained  at  an  average  of  48.4  bushels  for  the  corn 
crop  by  an  average  expenditure  of  $15.20  for  commercial 
fertilizers  (where  a  complete  fertilizer  was  used)  for  each 
course  of  the  rotation  (average  of  four  years).  These 
complete  fertilizers  were  fairly  well  mixed  to  meet  the 
needs  of  the  soils  in  each  case.  An  average  application  of 
11  tons  of  manure  every  four  years  has  maintained  the 
yield  of  corn  at  51.82  bushels. 

The  second  part  of  the  table  shows  the  average  financial 
returns  for  all  crops  grown  during  the  course  of  rotation. 
Eleven  tons  of  manure  shows  a  better  average  return  than 
$15.20  worth  of  commercial  fertilizer,  and  an  average 
return  of  $2.46  per  ton  for  the  manure.  The  Illinois 
station  received  a  return  of  $1.60  per  ton  and  the  Indiana 
station  $1.50  per  ton  for  manure.     Both  the  latter  stations 


ORGANIC  MATTER   FOR   CORN  LAND 


133 


are  on  newer  land,  where  as  large  increases  are  not  yet  to 

be  expected  as  on  old  cultivated  land. 

Again,  the  Ohio  station  ^  has  shown  that  the  value  of 

manure  may  be  increased  by  adding  and  composting  a 

small  amount  of  mineral  fertilizer  with  it.     The  following 

table  summarizes  the  data,  showing  a  marked  increase 

in  the  value  of  the  manure  where  treated  with  mineral 

fertilizer. 

TABLE  XXV 

Value  of  Barnyard  Manure  treated  with  40  Pounds  per 
Ton  of  Different  Minerals.  Applied  to  Crops  in 
A  Three-year  Rotation  of  Corn,  Wheat,  and  Hay  at 
THE  Rate  of  8  Tons  per  Acre.  Average  for  Fourteen 
Years 


Plats  No. 

Amendment 
Used 

Cost  of 
40  Pounds 

Cents 

Total  Value 
OF  Increase  in 
One  Rotation 

Net  Value  op 

Increase  per 

Ton  OF 

Manure 

2-3   ..     . 
5-6   .     .     . 

8-9   ..     . 
12-13      .     . 
15-16      .     . 

Floats 
Acid  phos- 
phate 
Kainit 
Gypsum 
Untreated 

18 

30 

34 

12 

0 

$33.51 

38.08 
29.28 
27.41 
23.44 

$4.01 

4.46 
3.32 
3.30 
2.93 

In  this  case,  the  mineral  was  mixed  with  the  manure  as  it 
was  removed  from  the  barns.  A  part  was  applied  directly 
to  the  land  in  each  case,  and  a  part  allowed  to  decay  in  the 
yards  for  about  three  months.  The  former  method 
seemed  to  be  the  better. 

SUMMARY 

96.  In  the  foregoing  discussion  on  the  theory  of  applying 
fertiUzers  and  manures  for  raising  cereals,  it  appears  that 
the  permanent  maintenance  of  the  soil  in  a  productive 

1  Ohio  Agr.  Exp.  Sta.,  Circ.  120  :  112.     1912. 


134  CORN   CROPS 

state  is  the  most  fundamental  problem  in  production. 
For  cereal  culture,  the  soil  must  be  maintained  at  the 
lowest  possible  cost.  The  four  principal  elements  to  be 
given  attention  in  most  soils  are  (1)  nitrogen,  (2)  phos- 
phorus, (3)  potash,  (4)  lime.  In  addition,  active  organic 
matter  must  be  present. 

These  conditions  are  met  in  the  most  practical  way  by : 

(1)  A  rotation  in  which  legumes  furnish  a  large  share  of 
the  nitrogen  used  by  other  crops  in  the  rotation. 

(2)  Where  manure  is  not  available,  practically  all 
organic  matter  grown  on  the  land,  with  the  exception  of 
threshed  grain,  should  be  plowed  under. 

(3)  In  order  to  maintain  the  full  supply  of  organic 
matter  and  nitrogen,  it  may  be  necessary  to  plow  under  the 
entire  legume  crop  without  harvesting. 

(4)  Where  live  stoch  is  kept,  all  manure  made  by  feeding 
produce  should  be  returned  to  the  land  in  relatively  light 
dressings. 

(5)  The  constant  removal  of  grain  will  gradually  reduce 
the  phosphorus  and  potassium.  This  must  be  returned 
as  commerical  fertilizer.  A  part  at  least  can  be  mixed 
with  the  manure  and  applied  in  this  way. 

(6)  Where  fertilizer  mixtures  are  applied  to  land,  careful 
regard  should  be  given  to  the  needs  of  the  land,  and  the 
fertilizer  should  be  mixed  to  meet  the  particular  needs  in 
each  case. 

(7)  Where  lime  is  required,  it  should  be  applied  once 
every  four  to  six  years,  the  amount  being  determined  by 
the  needs  of  the  land. 


CHAPTER  XIV 


MINERAL  MATTER  FOR   CORN  LAND 


As  pointed  out  heretofore  (p.  42),  about  1  per  cent  of 
the  green  weight  or  5  per  cent  of  the  dry  weight  of  corn  is 
ash  or  mineral  matter,  taken  directly  from  the  soil.  For 
the  production  of  50  bushels  of  corn  the  mineral  ash  found 
in  composition  would  be  as  follows  :  — • 

TABLE  XXVI 


Mineral  and  Nitrogen  Requirements  of 

CROPI 

A    50-BUSHEL 

Corn 

Nitro- 
gen 

Phos- 
phorus 

Potas- 
sium 

Mag- 
nesium 

Cal- 
cium 

Sul- 
fur 

Total 
Min- 
eral 

Total 
Ash 

Ears      (3500 
lb.)        .     . 

Stalks    (3000 
lb.)        .     . 

50.0 
24.0 

8.50 
3.00 

9.50 
26.00 

3.85 

4.80 

.7 
10.4 

.14 
3.00 

24.29 
64.40 

43.4 
69.5 

Total     . 

74.0 

11.50 

35.50 

8.65 

11.1 

3.14 

88.69 

112.9 

97.  Soils  in  regard  to  mineral  supplies  may  be  classed  as  : 

1.  Soils  in  which  sufficient  mineral  matter  in  available 
form  is  present. 

2.  Soils  in  which  sufficient  minerals  are  present,  but  one 
or  more  of  those  minerals  are  unavailable  or  available  in 
very  limited  amounts. 

3.  Soils  in  which  one  or  more  minerals  are  so  deficient 
that  even  with  good  soil  management  a  sufficient  amount 
cannot  be  made  available  for  a  crop,  the  total  supply 
being  sufficient  for  only  a  few  crops. 

1  Hopkins,  C.  G.     Soil  Fertility,  pp.  154  and  603. 
135 


136  COBN   CROPS 

The  first  class  included  most  of  the  present  Corn  Belt 
States  when  the  land  was  first  broken  up.  Large  crops 
were  grown  without  soil  amendments,  but  to-day  the  yield 
is  limited  on  most  of  these  soils  by  the  lack  in  available 
form  of  one  or  more  mineral  elements. 

In  the  second  class,  chemical  analysis  may  show  the 
presence  of  enough  minerals  and  nitrogen  for  fifty  to 
one  hundred  crops,  and  yet  the  crop  be  limited,  as  the 
minerals  may  become  available  only  very  slowly.  This 
class  includes  a  large  share  of  the  above-mentioned  soils 
that  have  been  farmed  fifty  to  one  hundred  years  or  more. 
Decreased  availability  of  minerals  may  be  due  to  several 
causes,  as  deficiency  in  bases  such  as  hme  or  magnesium, 
or  more  often  insufficient  organic  matter  in  a  state  of 
active  decomposition.  The  addition  of  lime  or  organic 
matter,  or  both,  is  the  evident  remedy  in  such  cases. 

In  other  cases  there  is  no  practical  way  of  making  avail- 
able sufficient  mineral  elements  for  maximum  crops,  and 
mineral  fertilizers  must  be  added.  In  many  soils  there 
are  other  inhibiting  factors  to  plant  growth,  even  when 
mineral  elements  are  abundant.  This  is  especially  true 
on  poorly  drained  soils  where  toxic  organic  compounds 
are  developed. 

In  class  3  are  included  many  of  the  sandy  soils  and  soils 
subject  to  leaching,  erosion,  or  derived  from  rocks  that 
originally  lack  some  mineral  in  composition.  It  is  doubt- 
ful whether  corn  culture  can  ever  be  profitably  developed 
on  land  of  this  class.  An  example  is  the  sandy  soil  of 
Long  Island,  where  most  of  the  mineral  must  be  supplied. 
Often  a  ton  or  more  per  acre  of  high-grade  fertilizer  is 
used.  On  such  land  only  crops  returning  a  large  gross 
income  per  acre,  as  potatoes,  cabbage,  or  truck,  can  be 
grown  with  profit. 


MINERAL   MATTER   FOR    CORN   LAND 


137 


98.  Hopkins  ^  believes  it  fair  to  "  assume  for  a  rough 
estimation  that  the  equivalent  of  2  per  cent  of  the  nitrogen, 
1  per  cent  of  the  phosphorus,  and  }  of  1  per  cent  of  the  total 
potassium  contained  in  the  surface  soil  can  be  made  avail- 
able during  one  season  by  practical  methods  of  farming." 

The  above  statement  is  borne  out  by  results  in  many  of 
the  prairie  soils  of  Illinois.  The  amount  of  nitrogen, 
phosphorus,  and  potassium  in  the  surface,  and  the  amount 
available  annually  on  the  above  basis,  is  shown  by  Hopkins 
to  be  as  follows  :  — 

TABLE  XXVH 

Fertility  in  Illinois  Soils   and  Amount   Annually   Avail- 
able IN  Pounds  per  Acre  (roughly  estimated) 


Average  per  Acre  in 

Surface  Soil  2 

Annually  Available  » 

(0-6|  IN.) 

Total 
Nitrogen 

Total 
Phos- 
phorus 

Total 
Potas- 
sium 

Nitro- 
gen 

Phos- 
phorus 

Potas- 
sium 

330 

Gray  silt  loam 

2,880 

840 

24,940 

58 

8 

62 

426 

Brown        silt 

loam      .     . 

4,370 

1,170 

32,240 

87 

12 

81 

520 

Black        clay 

loam      .     . 

6,760 

1,690 

29,770 

135 

17 

74 

635 

Yellow       silt 

loam      .     . 

2,390 

850 

37,180 

48 

9 

93 

1401 

Deep  peat 

34,880 

1,960 

2,930 

9 

20 

7 

AmoL 

mt  required  for 

50-busl 

lel  cor 

a  crop 

74 

11.5 

35.5 

From  the  above  typical  examples,  it  appears  that  many 
of  these  soils  do  not  meet  the  requirements  of  a  50-bushel 
corn  crop  in  all  the  three  elements  considered. 

1  Hopkins,  C.  G.,  I.e.,  p.  107.  '      - 

^Ibid.,  p.  82.  Ubid.,  p.  110. 


138  COBN   CROPS 

The  problem  of  production  on  soils  of  this  class  is  to 
increase  availability  through  use  of  manures  and  organic 
matter,  but  in  many  cases  the  addition  of  some  mineral 
supplement  is  now  necessary. 

FERTILIZERS    FOR   CORN 

99.  Theory  of  fertilizer  dosage.  —  If  a  perfectly  sterile 
sand  were  used  as  a  medium  for  growing  crops,  and  it  were 
desired  to  add  fertilizing  material,  the  logical  method 
would  be  to  ascertain  the  relative  amount  of  mineral 
constituents  in  the  plant  under  culture  and  add  the  minerals 
in  the  same  relative  proportion.  For  example,  the  three 
principal  mineral  constituents  in  the  corn  crop  is  shown  in 
Table  XXVI  to  equal,  in  a  50-bushel  corn  crop,  74.0  pounds 
of  nitrogen,  11.5  pounds  of  phosphorus  (or  26.3  phosphoric 
acid),  and  35.5  pounds  of  potassium  (or  42.6  potash) ; 
or  the  ratio  would  be  about  6 :  2  :  3  for  nitrogen,  phos- 
phoric acid,  and  potash. 

If  the  amount  of  fertilizer  applied  were  to  equal  the 
expected  crop,  then  for  a  50-bushel  corn  crop  we  should 
apply  about  the  following  formula  : 

74  lb.  nitrogen  =  400  lb.  sodium  nitrate 
11.5  lb.  phosphorus  =  190  lb.  acid  phosphate 
35.5  lb.  potassium    =    85  lb.  muriate  of  potash 

Fertihzer  for  corn  would  not,  however,  be  applied  to  a 
sterile  soil,  but  to  a  soil  usually  containing  enough  miner- 
als and  nitrogen  in  an  unavailable  state  for  fifty  to  one 
thousand  crops.  Organic  matter  and  lime,  and  thorough 
tillage,  assist  in  making  minerals  available ;  but  after  all 
reasonably  good  treatment  has  been  given,  some  one  or 
more  elements  may  be  found  available  only  in  such  small 
amount  that  the  crop  is  limited. 


MINERAL   MATTER    FOR    CORN  LAND 


139 


The  fertilizer  applied  should  be  planned  to  supply  the 
needed  element  or  elements,  rather  than  all  elements. 
Also,  a  certain  element  may  be  deficient  a  part  of  the  season 
but  more  plentiful  at  some  other  period.  This  is  true  of 
nitrogen,  which  is  often  deficient  in  early  spring,  especially 
on  heavy  clay  soils,  but  may  be  more  abundant  by  mid- 
summer. 

The  Ohio  Agricultural  Experiment  Station  reports  an 
experiment  in  which  fertilizers  were  applied  in  arbitrary 
quantities  in  comparison  with  plats  on  which  "  the  three 
fertilizing  elements,  nitrogen,  phosphorus,  and  potassium, 
are  given  in  approximately  the  same  ratio-  to  each  other 
in  which  they  are  found  in  the  plant."  ^ 

TABLE  XXVIII 

Fertilizer  Tests  with  Continuous  Corn  Culture  at  the 
Ohio  Agricultural  Experiment  Station.  Average  for 
Sixteen  Years,  1894-1909 


Plot 

Fertilizing  Materials 

Yield 

Increase 

No. 

■"   Pounds  per  Acre 

Grain 

Stover 

Grain 

Stover 

Bushels 

Pounds 

Bushels 

Pounds 

1 

None 

22.22 

1441 

2 

f  Acid  phos.      160]       ...   „ 

Mur.  potash  100     ^^^^'^^^^ 
I  Nitrate  soda  160  J  ^^^^^t''^' 
r  Acid.  phos.       601  ^^^^'^ 

42.71 

2326 

22.08 

949 

3 

\  Mur.  potash     30  \  in  corn 
I  Nitrate  soda  160  J  plant 

34.95 

1946 

15.90 

634 

4 

None        

17.46 

1248 

The  ratio  between  the  elements  in  the  two  mixtures  and 
that  required  by  the  plant  is  shown  in  the  following  state- 
ment :  — 

1  Ohio  Agr.  Exp.  Sta.,  Circ.  No.  104  •'  3.     1910. 


140 


CORN   CROPS 


Nitrogen 
Pounds 

Phosphoric 

Acid 

Pounds 

Potash 
Pounds 

Arbitrary  mixture     .... 

Ratio 

Natural  proportion  .... 

Ratio 

Elements  required  for  40 
bushels  corn 

Ratio 

24 

6 

24 

_6 

59 
6 

24 
_6 

8 

2_ 

21.2 
2 

50 
12 
15 
_4 

34.0 
3 

The  arbitrary  mixture  had  approximately  three  times 
the  phosphoric  acid  and  potash  in  proportion  to  nitrogen 
that  the  natural  proportion  showed. 

In  this  case  the  arbitrary  mixture  gave  the  best  results, 
as  the  crop  was  able  to  obtain  nitrogen  from  the  soil  to 
balance  the  fertilizer  applied.  The  point  is  well  illustrated 
in  a  second  experiment  in  which  the  fertilizer  mixtures  were 
compared.  The  fertilizer  was  applied  to  corn  in  a  three- 
year  rotation  of  clover,  corn,  and  wheat.  A  part  of  the 
benefit  of  the  fertilizer  went  to  the  wheat  and  clover. 
Results  with  all  three  crops  are  given  on  the  following 
page. 

Plot  19  received  a  smaller  application  of  fertilizer  at 
less  cost,  yet  it  contained  twice  as  much  phosphorus, 
which  seems  to  be  the  one  element  that  this  soil  most 
required . 

The  above  table  emphasizes  that  the  corn  grower  should 
handle  nitrogen,  phosphorus,  and  potassium  more  or  less 
independently,  adjusting  his  fertilizer  application  to  the 
needs  of  the  soil.  The  ready  mixed  fertilizer  will  not 
usually  be  as  profitable  as  the  fertilizer  mixed  especially 
for  the  case  concerned. 


MINERAL  MATTER   FOR   CORN  LAND  141 


TABLE   XXIX 

Showing  Fertilizers  applied  in  Certain  Experiments  at 
THE  Ohio  Agricultural  Experiment  Station  in  a  Three- 
years  Rotation  of  Clover,  Corn,  and  Wheat  ^ 


Plat 

Fertilizer 

Pounds  of  Elements 
APPLIED  per  Acre 

Cost 

Pounds  per  Acre 

Nitro- 
gen 

P2O5 

K2O 

PER 

Acre 

17 

18 

19 
20 

None 

[Nitrate  soda  160 

Acid  phos.       80 

IMur.  potash    80 

Ratio  .     .     . 
Tankage         100 
Acid  phos.       80 
.      Mur.  potash    10. 
None 

Approximate  rati< 
(See  table.) 

3  in  plant 

24 

7 
7 

7 

12.8 
4 
23 

2.5 

40 

11 

5 

4 

$7.45 
$2.30 

Corn,  Twelve 
Crops 

Average  Annual  Increase  per  Acre 

Value 
OF  In- 
crease 

PER 

Acre 

Plat 

Grain 
Bushels 

Stover 
Pounds 

Corn 
Grain 
Bushels 

Twelve 
Crops 
Stover 
Pounds 

Wheat 
Grain 
Bushels 

Twelve 
Crops 
Straw 

Pounds 

Hay 
Pounds 

Cost  of 
Treat- 
ment 

17 

18 
19 
20 

36.55 
43.12 
44.37 
34.09 

2303 

2587 
2456 
2025 

9.25 
10.50 

471 

348 

2.83 
4.07 

309 
510 

599 

718 

$7.45 
$2.30 

$9.37 
$11.36 

pp.  17-18. 


142 


CORN   CROPS 


FERTILIZER    MIXTURES    FOR    CORN 

100.  To  mix  the  fertilizer  so  as  to  suit  the  requirements 

of  the  particular  soil  and  crop,  is  the  ideal  way.     As  a 

basis  for   use  when  the  fertilizer  requirements   are   not 

known,   general   experience  indicates  that   a  formula  of 

about  3-8-5  will  most  often  be  satisfactory.    The  Maine 

Agricultural  Experiment  Station  ^  suggests  the  following 

formula :  — 

TABLE  XXX 

Formulas  for  Fertilizers  suggested   by  the  Maine  Agri- 
cultural Experiment  Station 


Crop  and  Fertilizing  Material 


Corn  on  sod  land,  or  in  conjunction 
with  farm  manure. 

Nitrate  of  soda 

Acid  phosphate 

Muriate  of  potash 

Total 

Percentage  composition  .     .     . 

Nitrate  of  soda 

Screened  tankage 

Acid  phosphate 

Muriate  of  potash 

Total 

Percentage  composition 

Nitrate  of  soda 

Cottonseed  meal 

Acid  phosphate 

Muriate  of  potash 

Total 

Percentage  composition  .     .     . 


Weight 

Used 
Pounds 


100 
400 
150 


650 


100 
200 
300 
150 


750 


100 
200 
400 
150 


850 


Nitro- 
gen 
Pounds 


16 


16 

2.S 

16 
11 


27 
3.6 

16 
14 


30 
3.5 


Phos- 
phoric 
Acid 
Avail- 
able 
Pounds 


52 


52 

8.0 


15 
39 


54 

7.2 


52 


52 

6.1 


Potash 
Pounds 


75 


75 
11.5 


75 


75 
10 

4 

75 


79 
9.3 


1  Maine  Agr.  Exp.  Sta.,  Bui.  107.     1904. 


MINERAL   MATTER   FOR   CORN  LAND 


143 


Director  Charles  D.  Woods,  who  prepared  the  above 
formulas,  makes  the  following  statement  in  connection 
therewith:  "Corn  is  a  crop  that  uses  a  large  amount  of 
nitrogen.  It  is  usually  grown  upon  sod  land  or  with  farm 
manure,  or  both.  Indeed,  it  is  doubtful  if,  under  ordinary 
conditions,  it  would  prove  a  profitable  crop  to  be  grown 
on  somewhat  exhausted  soil  with  commercial  fertilizers 
alone.  .  .  .  The  first  formula  contains  only  about  one- 
sixth  of  the  nitrogen  needed  to  grow  the  crop.  With  a 
good  sod  and  especially  with  a  liberal  dressing  of  farm 
manure,  that  will  l)e  all  that  is  needed.  The  second  and 
third  formulas  carry  more  nitrogen.  ..." 

101.  The  New  York  (Geneva)  Agricultural  Experiment 
Station  ^  suggests  the  following  formulas  for  corn  :  — 

TABLE   XXXI 


Pounds  of  Different  Constituents 

i  FOR  One  Acre 

Formula 

Principal  Source  of 

Principal  Source  of 

Principal  Source  of 

Nitrogen 

Phosphoric  Acid 

Potash 

1 

i 

60  to  100  lb.  ni-  !  350  to  700  lb. 

60    to    120    lb. 

trate  of  soda 

bone  meal 

muriate        of 
potash 

2 

50    to    100    lb. 

250  to  500  lb. 

60    to    120    lb. 

sulphate      of 

dissolved 

sulphate       of 

ammonia 

bone 

potash 

3 

100  to  200  lb.     300  to  600  lb. 

250   to   500   lb. 

dried  blood 

dissolved 
rock 

kainit 

4 

3000  to  4000  lb. 

600  to  1200  lb. 

stable  manure 

wood  ashes 

Pounds  per 

Nitrogen  10  to 

Available  phos- 

Potash 30  to  60 

acre    .     . 

20 

phoric     acid 
35  to  70 

Percentage 

2 

7 

6 

N.  Y.  (Geneva)  Agr.  Exp.  Sta.,  Geneva,  N.Y.,  14th  Rept. 


144 


CORN   CROPS 


102.  As  soils  are  continuously  cropped,  progressive 
changes  take  place.  A  suggested  method  of  adapting  the 
fertilizer  to  conditions  is  given  by  C.  E.  Thorne  of  the 
Ohio  Agricultural  Experiment  Station,  as  indicated  by 
experience  on  rather  poor  glacial  soil  at  that  station :  ^  — 

TABLE  XXXII 

Fertilizers  suggested  for  Different  Conditions 


Percentage  Composition 

Conditions 

Ammonia 

Phosphoric 
Acid 

Potash 

For  crops  immediately  follow- 
ing clover 

For  crops  one  or  two  years 
after  clover        

For  crops  two  or  three  years 
after  clover        

For  crops  on  exhausted  soils    . 

1 

3 

4 

6 

13 
12 

12 

12 

2 

3 

4 
6 

WHEN   IT   PAYS    TO    FERTILIZE    FOR    CORN 

103.  The  gross  income  per  acre  from  cereal  crops  is  low, 
and  their  extensive  culture  can  be  carried  on  only  where 
the  soil  naturally  furnishes  most  of  the  mineral  elements 
without  excessive  cost.  In  the  past,  cereal  culture  has 
largely  followed  the  opening  up  of  new  lands,  while  it  has 
declined  on  old  soils  when  extensive  use  of  commercial 
fertilizers  has  become  necessary. 

From  the  foregoing  discussion  it  seems  that  the  use  of 
mineral  fertilizers  for  corn  can  be  applied  at  a  profit  only 
as  a  supplement  to  soils  already  well  supplied  with  avail- 
able  minerals.     In   many   cases  when   a   single   mineral 

1  Ohio  Agr.  Exp.  Sta.,  Bui.  141.     1903. 


MINERAL   MATTER   FOR   CORN  LAND  145 

element  is  lacking  in  an  available  from,  this  element  may 
often  be  directly  supplied  at  a  profit;  but  ordinarily, 
in  order  to  obtain  the  highest  availability  from  the  min- 
erals, fertilizers  must  be  used  in  connection  with  barnyard 
manures,  and  in  a  properly  balanced  crop  rotation  where 
most  of  the  nitrogen  is  supplied  by  legumes  and  the  soil  is 
kept  well  supplied  with  decaying  organic  matter. 

A  review  of  the  experimental  evidence  regarding  the 
use  of  commercial  fertilizers  for  corn  seems  to  justify  the 
following  principles. 

1.  It  seldom  pays  to  use  mineral  fertilizers  alone  on 
land  in  a  low  state  of  fertility  or  on  land  that  would  not 
produce  more  than  20  bushels  of  corn  per  acre  under 
favorable  conditions.^ 

2.  Even  on  good  land  it  seldom  pays  to  apply  mineral 
fertilizer  alone  directly  to  the  corn  crop.- 

3.  It  seldom  pays  to  use  fertilizers  where  corn  is  grown 
continuously  or  where  it  is  rotated  with  grain  crops  only. 
Under  such  conditions,  according  to  the  Ohio  station, 
only  60  per  cent  of  the  fertilizer  is  recovered  in  the  crop.^ 

4.  Commercial  fertilizer  pays,  as  a  rule,  only  when  used 
in  connection  with  a  rotation  where  manure  or  a  legume 
crop,  or  both,  are  plowed  under.^  In  this  case  it  is  usually 
best  to  apply  the  fertilizer  to  the  sod  land,  or,  when  wheat 
is  grown  in  the  rotation,  a  part  may  be  applied  to  the  wheat, 
The  above  expecially  applies  to  phosphates  and  potash. 
Sodium  nitrate  is  a  partial  exception  to  the  above  general 
rule,  as  it  is  sometimes  apphed  with  profit  to  the  growing 
corn. 

1  U.  S.  Dept.  Agr.,  Farmers'  Bui.  744  ;  10;  Farmers'  B\x\.  414  :  12. 
1910.     R.  I.  Agr.  Exp.  Sta.,  Bui.  113:  113.      1906. 

2  Ind.  Agr.  Exp.  Sta.,  Bui.  77  :  32.      1899. 

3  Ohio  Agr.  Exp.  Sta.,  Bui.  110  :  68.   *  1899. 

4  U.  S.  Dept.  Agr.,  Farmers'  Bui.  lU  :  10.     1901. 

L 


146  CORN  CROPS 

Special  cases :  There  are  exceptions  to  the  above  rules, 
a  striking  example  of  which  are  certain  rich  muck  lands  in 
Illinois,  well  supplied  with  all  elements  except  potassium, 
where  an  application  of  potassium  salts  pays  large  returns.^ 

It  is  not  to  be  inferred  that  fertilizers  do  not  afford  a 
stimulus  and  give  increased  production,  for  they  do ;  but 
the  gross  income  from  an  acre  of  corn  is  not  sufficiently 
increased  to  pay  the  cost  of  fertilizer,  except  in  certain 
cases  when  used  in  connection  with  manure  and  legumes. 
This  makes  it  apparent  that  profitable  corn  growing 
must  be  carried  on  as  a  part  of  a  general  farming  scheme 
in  which  the  soil  fertility  is  principally  maintained  by  the 
use  of  green  manures  or  barnyard  manure,  which  may  be 
supplemented  in  a  limited  way  with  commercial  fertilizer. 

NITROGEN 

104.  A  large  or  excessive  supply  of  available  nitrogen  is 
not  considered  favorable  for  most  of  the  cereals,  as  wheat, 
oats,  or  barley;  the  effect  being  to  produce  an  excessive 
growth  of  straw,  and  often  a  decreased  yield  of  grain. 
Corn,  however,  is  not  so  affected,  and  is  most  productive 
on  heavily  manured  land  or  on  newly  drained  alluvial  or 
swamp  lands  where  the  available  nitrogen  is  so  abundant 
that  wheat  or  oats  would  "  run  to  straw  "  and  produce 
little  or  no  grain.  In  fact,  a  well-manured  clover  sod 
where  available  nitrogen  is  in  greater  excess  than  any 
other  necessary  element  is  ideal  corn  land. 

A  large  supply  of  nitrogen  has  sometimes  been  found  a 
disadvantage  early  in  the  season,  as  it  may  stimulate  a 
growth  of  plant  too  large  to  be  adequately  maintained 
during  the  remainder  of  the  season.     For  example,  the 

1  Hopkins,  C.  G.     Soil  Fertility  and  Permanent  Agricultiire,  p.  471. 


MINERAL   MATTER  FOR   CORN  LAND  147 

"  Williamson  "  ^  method  of  corn  culture  advocates  the 
withholding  of  soluble  nitrate  fertilizer  until  the  plants 
are  six  to  eight  weeks  old,  thus  tending  to  retard  stalk 
growth  but  to  give  the  needed  stimulus  at  the  time  when 
ears  are  forming. 

West  of  the  Missouri  River,  where  the  soil  is  loose  and 
nitrification  begins  early  in  the  season,  it  often  happens 
that  on  very  fertile  soil  a  vigorous  spring  growth  is  stimu- 
lated, and  later,  if  the  season  proves  unusually  dry,  the 
growth  cannot  be  sustained ;  and  such  fields  suffer  more 
than  do  fields  in  a  less  fertile  condition.  On  the  other 
hand,  with  abundant  water  supply  those  fields  would  have 
been  more  productive. 

LIME 

105.  Lime  is  an  essential  element  required  by  plants. 
It  is  not  commonly  applied  as  a  fertilizer,  as  only  about 
12  pounds  of  lime  are  required  by  a  50-bushel  corn  crop, 
and  most  soils  are  abundantly  supplied  in  so  far  as  having 
sufficient  lime  for  plant  growth  is  concerned. 

The  most  important  use  of  lime  is  as  a  soil  amendment, 
when  it  assists  in  several  ways  in  making  the  soil  more 
favorable  for  plant  growth  :  — 

1.  Acid  in  the  soil  is  neutrahzed. 

2.  Potash  and  phosphate  in  the  soil  are  made  more 
readily  available. 

3.  Organic  matter  decays  more  rapidly  and  the  organic 
nitrogen  and  minerals  become  available  to  plants  in  less 
time. 

4.  The  soil  is  made  a  more  favorable  medium  for  bene- 
ficial bacteria  forms. 

1  The  Williamson  Plan.     S.  C.  Agr.  Exp.  Sta.,  Bui.  135.     1908. 


148 


CORN   CROPS 


5.  The  mechanical  condition  of  heavy  clay  soils  is 
improved. 

According  to  Bulletin  64  of  the  Bureau  of  Soils,  United 
States  Department  of  Agriculture,  one  hundred  sixty-eight 
experiments  with  lime  for  corn  have  been  reported  by 
experiment  stations.  The  average  increase  reported  is 
3.2  bushels  per  acre  at  a  cost  of  $8.91  for  the  lime.  For 
corn  soils  in  general  liming  would  not  pay,  but,  on  the 
other  hand,  certain  experiments  show  large  profits  from 
the  use  of  lime. 

The  Tennessee  station  reports  an  increased  yield,  at  less 
cost  per  bushel,  than  for  any  of  a  number  of  mineral  fer- 
tilizers tried  in  comparison,  as  shown  in  the  following 
table :  — 

TABLE  XXXIII 
Fertilizers  with  Hickory  King  Corn,  1901-1902 


Cost  of 
Fertilizer 
PER  Acre 

Yield  per 

Increase 

Cost  per 

Fertilizer  Used 

Amount 

Acre  of 
Grain 

Due  to 
Fertilizer 

Bushel 
of 

Bushels 

Bushels 

Increase 

No  fertilizer     . 

. 

41.94 

Farmyard 

manure    .     . 

8  tons 

$3.20 

48.71 

6.77 

$0.47 

Lime       .     .     . 

25 

bushels 

1.50 

49.22 

7.28 

.10 

[  Nitrate       of 

100 

soda      -     . 

pounds 

Acid      phos- 

150 

phate   . 

pounds 

4.00 

43.97 

2.03 

1.74 

Muriate      of 

5 

potash 

pounds 

At  the  Ohio  station  ^  the  addition  of  lime  increased  the 
yield  of  corn  10  bushels  per  acre,  or  about  30  per  cent,  both 

1  Ohio  Agr.  Exp.  Sta.,  Bui.  159  :  173. 


MINERAL   MATTER   FOR   CORN  LAND  149 

on  plats  where  lime  was  used  alone  and  where  it  was  used  in 
connection  with  other  fertilizers.  In  commenting  on 
results  with  lime,  Director  Thorne  says  :  — 

"  Taking  the  results  as  a  whole,  it  would  seem  that  the 
Hme  has  performed  two  distinct  offices  in  this  test :  in  the 
first  place,  it  has  increased  the  yield  by  an  average  of 
about  10  bushels  per  acre,  or  30  per  cent  of  the  unfer- 
tilized yield.  This  it  must  have  done  in  one  or  both  of 
two  ways ;  either  it  has  furnished  a  needed  element  of  plant 
food  to  the  growing  crop,  or  else  it  has  rendered  the  plant 
food  already  in  the  soil  more  available,  either  by  direct 
chemical  action  of  the  lime  itself  on  the  soil  stores  of  nitro- 
gen, phosphorus,  and  potassium,  or  by  opening  up  the  soil 
and  giving  the  air,  water,  and  frost  a  better  opportunity  to 
reach  these  stores  and  prepare  them  for  plant  nutrition. 

"  The  other  office  performed  by  the  lime  seems  plainly 
to  have  been  the  setting  up  of  conditions  favorable  to  the 
growth  in  the  soil  of  the  micro-organisms  by  which  the 
stores  of  organic  nitrogen  are  gradually  converted  into 
available  form  through  the  process  of  nitrification.  This 
is  indicated  by  the  fact  that  the  giving  of  large  quantities 
of  available  nitrogen  in  the  fertilizers  appears  to  have 
reduced  the  effect  ascribable  to  lime,  whereas  this  effect 
seems  to  have  been  augmented  by  fertilizers  containing 
little  or  no  nitrogen." 

It  may  be  said  in  general  that  lime  as  a  soil  amendment  is 
more  likely  to  be  beneficial  on  heavy  clay  soil,  in  humid 
regions,  where  aeration  is  poor  and  the  products  of  organic 
decomposition  are  very  likely  to  be  toxic  to  plants.  In 
regions  of  low  rainfall  or  sandy  soils,  lime  is  not  so  likely 
to  be  required  as  a  soil  amendment. 

There  are  various  chemical  tests  for  determining  the 
probable  lime  requirement  of  a  soil,  but  the  most  reliable 


150  CORN   CROPS 

test  is  to  apply  lime  experimentally  and  note  results  for  at 
least  two  years. 

References  on  fertilizers  :  — 

VooRHEEs,  E.  B.     (1898.)     Fertilizers. 

Lyon  and  Fippin.      (1909.)     Soils,  pp.  267-386. 

Bailey,  L.  H.  (1911.)  The  Farm  and  Garden  Rule  Book, 
pp.  40-91. 

Hopkins,  C.  G.  (1910.)  Soil  Fertility  and  Permanent  Agri- 
culture. 

Ohio  Agr.  Exp.  Sta.,  Bui.  141 ;   Circ.  104. 

Maine  Agr.  Exp.  Sta.,  Bui.  107. 

Vt.  Agr.  Exp.  Sta.,  Bui.  116;   Circ.  7. 

References  on  lime  :  — 
Agriculture  Lime.     Conn.  (Hatch)  Agr.  Exp.  Sta.,  Bui.  163. 
Lime  and  Liming.     R.  I.  Agr.  Exp.  Sta.,  Bui.  46. 
Chemical  Methods  of  Ascertaining  Lime  Requirements  of  Soils. 

R.  I.  Agr.  Exp.  Sta.,  Bui.  62. 
Liming  Acid  Soils.     U.  S.  Dept.  Agr.,  Farmers'  Bui.  133. 
Liming  the  Soil.     Ohio  Agr.  Exp.  Sta.,  Bui.  159. 
Carriers  of  Lime.     Ohio  Agr.  Exp.  Sta.,  Circ.  123. 
The  Rational  Use  of  Lime.     Mass.  Agr.  Exp.  Sta.,  Bui.  137. 
Increasing    the   Yield   of   Corn.      Tenn.   Agr.    Exp.   Sta.    Bui., 

Vol.  XVII,  No.  2,  p.  46. 
The  Use  of  Lime  upon  Pennsylvania  Soils.     Penn.   Dept.  of 

Agr.,  Bui.  61.     1900. 


CHAPTER  XV 

REGULATING   THE  WATER  SUPPLY 

A  50-BUSHEL  corn  crop  requires  7  to  10  inches  of  water 
for  the  use  of  the  plant,  besides  that  to  be  allowed  for 
run-off,  seepage,  and  evaporation.  In  Nebraska,  with  a 
29-inch  rainfall,  the  division  of  this  water  between  the 
four  sources  of  losses  is  estimated  as  follows,  when  a  50- 
bushel  crop  is  grown  :  — 

Water  required  by  the  plants 8  inches 

Water  lost  by  run-oft' 3  inches 

Water  lost  by  seepage        2  inches 

Balance  lost  by  evaporation        16  inches 

Total 29  inches 

The  proportion  of  total  rainfall  lost  by  the  different 
means  will  vary  with  the  region,  })ut  it  is  probable  that 
in  most  cases  evaporation  is  twice  the  amount  required  by 
the  crop. 

106.  Not  all  evaporation  is  undesirable.  Whenever  the 
soil  reaches  its  water-holding  capacity,  as  is  often  the  case 
in  early  spring,  then  it  must  be  dried  by  evaporation  before 
cultivation  can  be  practiced.  Run-off  is  desirable  after  the 
soil  reaches  saturation,  if  the  run-off  takes  place  in  such  a 
way  as  not  to  cause  erosion,  since  the  taking  up  of  this 
water  by  the  soil  would  increase  the  loss  by  drainage,  and 
excessive  drainage  means  a  slow  leaching  of  the  soil. 
The  amount  of  run-off  necessary  in  order  to  care  for  ex- 
cessive rainfall,  or  of  evaporation  necessary  in  order  to 
dry  out  the  soil,  will  vary  with  the  rainfall.  In  fact,  all 
the  water  above  that  actually  used  by  the  crop  is  exces- 

151 


152 


CORN   CROPS 


sive  and  must  be  disposed  of  in  some  way,  as  by  drainage, 
run-off,  or  evaporation. 

Even  though  the  crop  requires  a  relatively  small  pro- 
portion of  the  total  rainfall,  the  crop  often  suffers  due  to 
the  fact  that  this  small  proportion  is  required  during  a  com- 
paratively short  period  and  in  excess  of  the  water-storing 
capacity  of  the  soil. 

Lyon  and  Fippin  ^  give  the  following  statement  regarding 
the  water-holding  capacity  of  some  soils  :  — 

TABLE  XXXIV 


Water  Capacity 

Amount  of  Available  Water 

Minimum 
Per  Cent 

Maximum 
Per  Cent 

Per  Cent 

Cu.  in.  per 
Cu.  ft. 

Inches  per 
Acre,  4  ft. 

Light       sandy 

loam         .     . 

Silt  loam      .     . 

Clay        .     .     . 

3 
15 
23 

8 
25 
40  2 

5 
10 
17 

122 

218 
274 

3.4 
6.0 
7.6 

Studies  at  the  Nebraska  station  indicate  the  water 
requirements  of  a  50-bushel  corn  crop  for  the  different 
months  to  be  about  as  follows  :  — 


TABLE  XXXV 


Inches 


January  1  to  June  1 

June 

July 

August 

September   .... 
October  1  to  January  1 
Total    .... 


.00 

.50 

3.60 

3.30 

.60 

00 

8.00 


Lyon  and  Fippin.     Soils,  p.  158. 


2  Assumed. 


REGULATING    THE    WATER   SUPPLY  153 

Most  of  this  water  is  required  during  a  period  of  five  oi 
six  weeks,  ranging  from  about  July  10  to  the  end  of  August. 
On  p.  65  it  was  pointed  out  that  evaporation  from  the  soil 
and  loss  from  run-off  probably  equals  or  nearly  equals 
the  requirements  of  the  plants  in  making  a  50-bushel  crop, 
or  the  total  requirement  by  the  crop,  and  evaporation 
from  the  soil,  etc.,  for  July  and  August  probably  amounts 
to  12  inches.  This  is  twice  the  storage  capacity  of  the 
soil  and  perhaps  three  times  the  amount  usually  available 
early  in  July.  After  the  water  stored  in  the  soil  is  ex- 
hausted, if  rains  are  delayed,  the  crop  suffers,  being 
greatly  reduced,  and  this  often  happens  even  when  abun- 
dant rains  come  later.  The  seasonal  requirements  of  corn 
are  illustrated  by  Fig.  24. 

107.  Three  ways  are  open  for  regulating  the  water 
supply :  (a)  increasing  the  water-holding  capacity  of  the 
soil;  (6)  conservation  by  preventing  evaporation;  (c) 
decreasing  run-off  during  the  growing  season. 

Since  the  water-storage  capacity  of  soil  is  closely  related 
to  its  physical  composition,  little  can  be  done  to  improve 
this  condition  in  a  practical  way.  The  addition  of  vege- 
table matter  helps  only  to  a  limited  extent. 

A  certain  amount  of  evaporation  can  be  prevented  by 
cultivation,  but  how  much  has  never  been  satisfactorily 
determined  under  field  conditions.  It  is  probable,  how- 
ever, that  loss  by  evaporation  of  water  that  has  reached  a 
depth  of  12  inches  in  the  soil  is  very  small,  and  that  culti- 
vation serves  principally  to  prevent  evaporation  of  mois- 
ture from  rains  that  penetrate  no  deeper  than  6  to  10 
inches.  Experimental  results  under  field  conditions  to 
show  the  effect  of  cultivation  give  extraordinary  variation. 
For  example,  at  the  Illinois  Agricultural  Experiment 
Station,  plats  of  corn  that  were  not  cultivated  but  merely 


154  CORN  CROPS 

had  the  weeds  shaved  off  gave  as  good  results  as  an  aver- 
age of  five  years  as  when  carefully  cultivated,  and  similar 
results  have  been  secured  at  other  stations.  (See  p.  206.) 
On  other  occasions  cultivation  has  apparently  conserved 
sufficient  moisture  to  improve  the  yield.  The  underlying 
principles  have  not  been  clearly  worked  out. 

It  seems  apparent  that  a  well-cultivated  surface,  with 
a  good  store  of  organic  matter,  will  take  up  a  moderate 
rain  more  readily  and  store  a  large  percentage  of  it  deep 
enough  to  protect  from  surface  evaporation  than  will  a 
hard  and  uncultivated  surface ;  also,  that  when  this  mois- 
ture is  stored  continued  cultivation  will  decrease  the  rate 
of  loss  from  the  upper  10  inches  of  surface. 

EROSION 

108.  Effect  of  erosion.  —  Erosion  affects  the  agricul- 
tural value  of  land  in  the  two  ways :  first,  by  producing 
gullies  and  large  ditches,  thus  increasing  the  expense  of 
crop  cultivation  and  resulting  in  the  actual  loss  of  some 
land;  second,  by  reducing  available  fertility,  through 
removing  the  surface. 

In  the  latter  case,  the  damage  to  productivity  depends 
on  the  soil.  In  heavy  clay  soils,  much  of  the  available 
fertility  seems  to  be  in  the  surface  6  inches.  On  such 
soil  productivity  is  often  reduced  for  many  years  by  turn- 
ing up  too  much  subsoil  at  one  time  with  the  plow.  On 
the  other  hand,  as  pointed  out  by  King,^  in  many  regions, 
especially  of  low  rainfall,  the  subsoil,  even  to  several 
feet  deep,  is  as  productive  as  the  surface  soil.  In  a  case  of 
such  surface,  erosion  would  work  little  or  no  damage. 
However,  in  most  of  the  regions  where  erosion  is  severe, 

1  King,  F.  H.     The  Soil,  p.  29. 


REGULATING    THE   WATER   SUPPLY  155 

as  in  eastern  United  States,  the  soil  is  heavy  in  texture, 
the  exposed  subsoil  not  productive,  and  the  loss  of  surface 
soil  causes  serious  damage.  When  manure,  mineral 
fertilizer,  or  lime  is  used,  much  of  this  added  material 
remains  in  the  plowed  surface  and  erosion  causes  a  direct 
loss  of  this  material. 

109.  Causes  of  erosion.  —  In  the  corn-growing  area  of 
the  United  States  — •  that  is,  from  the  Atlantic  Coast 
westward  to  the  100th  meridian  —  erosion  is  related  to 
the  amount  of  run-off  water  and  to  the  condition  of  the 
soil  at  the  time  the  run-off  takes  place.  In  the  principal 
corn-growing  States,  north  and  west  of  the  Ohio  River, 
erosion  is  not  serious.  The  land  is  generally  level  and 
rainfall  not  excessive.  Also,  during  a  part  of  the  year  the 
ground  is  frozen,  and  in  June,  July,  and  August,  when 
about  40  per  cent  of  the  rainfall  occurs,  the  land  is  in  crop. 

From  Ohio  eastward,  however,  the  rainfall  is  heavier  and 
cultivated  land  is  more  rolling,  thus  increasing  the  total 
run-off  and  erosion.  From  the  western  edge  of  the  Corn 
Belt  to  the  Atlantic  Coast,  erosion  gradually  increases. 
In  Kansas  and  Nebraska,  with  level  farming  land,  the 
rainfall  is  25  to  30  inches  and  the  total  run-off  about  3 
inches.  In  the  North  Atlantic  States  rainfall  is  heavier, 
land  more  rolling,  and  the  run-off  is  estimated  at  40  to  50 
per  cent  of  the  rainfall,  which  often  amounts  to  a  run-off  of 
20  inches  or  more.  In  the  Southern  States  the  most 
serious  erosion  takes  place  during  the  winter  months. 
The  soil  is  not  frozen,  is  without  a  crop,  and  heavy  rainfall 
occurs  during  this  period. 

The  relation  of  cropping  systems  to  erosion  may  be 
grouped  as  follows  :  — 

(a)  Land  in  grass  erodes  least. 

(6)  Land  in  stubble  or  small  grain  erodes  more  than  (a). 


156  CORN   CROPS 

(c)  Land  in  cultivated  crops  erodes  more  than  (6) . 

(d)  Cultivated  land  not  in  crops  erodes  most. 

110.  Preventing  erosion.  —  Since  the  character  of  the 
crop  and  the  grade  of  the  land  both  have  a  marked  effect 
on  the  degree  of  erosion,  they  are  the  two  principal  means 
of  preventing  the  same. 

Land  subject  to  severe  erosion  should  be  kept  principally 
in  grass  crops  and  small  grain,  and  never  left  longer  than 
necessary  without  a  growing  crop.  If  a  good  supply  of 
vegetable  matter  is  maintained  and  deep  plowing  practiced, 
cultivated  crops  can  often  be  grown  on  rolling  land  with 
little  loss  by  erosion  where  otherwise  the  loss  would  be 
severe.  It  is  often  noted  that  new  land  just  brought  under 
cultivation  does  not  erode,  but  as  the  humus  supply 
decreases,  erosion  increases.  Also,  the  plowing  under  of  a 
heavy  coat  of  barnyard  manure  or  a  green  manure  crop 
will  often  stop  erosion  where  it  is  otherwise  serious.  Deep 
plowing  enables  the  soil  to  take  up  water  readily  and  give 
it  up  slowly,  and  in  many  cases  deep  plowing  alone  has 
been  found  to  entirely  prevent  erosion. 

The  second  method  of  preventing  erosion  is  by  decreas- 
ing the  grade.  This  is  usually  clone  by  terracing,  causing 
the  water  to  follow  the  contour  of  the  hills  at  a  low  grade. 
The  same  effect  is  secured  in  some  degree  by  plowing  and 
planting  with  the  contour  of  the  hills. 

To  summarize :  Erosion  is  better  controlled  when  the 
land  is  in  grass  or  small  grain  than  when  in  a  hoed  crop. 
Sufficient  organic  matter  and  deep  plowing  decrease  erosion. 
The  land  should  not  be  left  bare.  The  grade  can  often  be 
decreased  by  terracing. 

The  most  serious  loss  due  to  erosion  is  the  constant  re- 
moval of  the  accumulated  organic  matter  of  the  surface 
soil. 


BEGULATING    THE   WATER    SUPPLY  157 


DRAINAGE 

111.  Corn  requires  a  thoroughly  drained  soil,  both  be- 
cause it  flourishes  in  a  "  warm  "  soil,  and  because  it  re- 
quires large  amounts  of  available  nitrates  when  making  its 
rapid  summer  growth.  On  poorly  drained  land,  even 
when  such  land  is  rich  bottom  soil,  the  corn  plant  will 
often  have  a  yellow  color  indicating  a  need  of  nitrogen. 


fl^ 


A^  ^^ 


WATER 
FURROW 


8  FT. 


Fig.  40.  —  Plan  of  ridging  land  for  surface  drainage.    Two  rows  on  each 

ridge. 

The  water-logged  soils  interfere  with  bacterial  activity 
and  the  normal  nitrifying  processes  are  prevented.  Sur- 
face drainage  for  corn  on  very  flat  lands  is  often  provided 
by  plowing  in  narrow  beds,  8  feet  wide,  and  planting  two 
rows  of  corn  4  feet  apart  on  each  bed. 

Underdrainage  is  so  thoroughly  discussed  in  several 
soil  texts  that  it  is  not  necessary  to  take  up  the  subject 
here. 


SECTION  IV 
CULTURAL  METHODS 


CHAPTER  XVI 
PREPARATION  AND   PLANTING 

So  far  in  this  book  it  has  been  the  plan  to  discuss  the 
fundamentals  relating  to  the  nature  of  the  corn  plant,  its 
requirements,  the  conditions  that  must  be  met  in  the  grow- 
ing of  corn,  and  methods  of  modifying  the  plant  to  im- 
prove yield  or  quality. 

Having  considered  the  above  problems,  the  next  step 
is  to  consider  cultural  methods.  The  basic  principle  in 
cultural  methods  is  largely  protection  of  the  crop  against 
unfavorable  conditions  that  may  arise,  as  draught,  weeds, 
insect  or  parasitic  enemies.  The  cultural  method  to  be 
adopted  in  a  particular  case  is  the  one  that  most  effec- 
tually insures  the  crop,  and  at  the  least  cost. 

Cultural  methods  must  vary  with  the  local  situation. 
In  regions  of  high  priced  labor  and  level  lands,  extensive 
systems  have  been  developed.  In  regions  of  low  priced 
labor  and  small  fields  more  intensive  methods  are  prac- 
ticed. The  other  crops  to  be  grown,  the  character  of  the 
chmate,  the  use  of  the  crop,  and  many  other  factors  all 
help  to  determine  the  most  practical  method  to  be 
adopted.  As  with  other  farm  problems,  the  farmer  him- 
self must  largely  determine  the  cultural  method  to  be 
used  on  his  own  farm. 

THE    OLD    CORN    STALKS 

112.  In  the  corn-belt  and  the  Southern  States,  corn  stalks 
are  not  harvested,   but  stand  in  the  fields,  to  be  plowed 
M  161 


162 


COBN  CROPS 


under  the  following  spring.  In  the  early  days  of  corn 
culture  in  the  middle  west,  the  corn  stalks  were  usually 
burned.  The  common  custom  was  to  break  down  the 
frozen  stalks  with  a  log  or  an  iron  rail  and  later  when  the 
ground  had  thawed,  they  were  raked  with  horse  rakes 
into  long  windrows,  and  burned.  For  a  week  or  two  in 
each  spring,  the  sky  would  be  lit  up  every  night  by  the 


Fig.  41.  —  Two-row  stalk-cutter. 


great  burning  fields  of  corn  stalks.  This  so  rapidly  re- 
duced the  organic  matter  in  the  soil  that  it  soon  became 
necessary  to  plow  the  stalks  under,  as  is  now  the  general 
custom,  in  order  to  obtain  humus. 

To  prepare  for  plowing,  the  stalks  are  broken  with  a  rail, 
as  before,  and  then  usually  gone  over  with  a  sharp  disk, 
to  cut  them  up.  The  stalk-cutter  is  also  in  general  use. 
This  implement  has  heavy  revolving  cylinders  set  with 
knives  that  cut  the  stalks  in  twelve  inch  lengths.  Where 
the  stalks  are  heavy  it  is  more  satisfactory  than  the  disk 
harrow,  although  the  stalk-cutter  is  often  followed  also 
with  a  disk-harrow. 


PREPARATION  AND  PLANTING  163 


TIME   OF   PLOWING 

113.  When  land  is  fall-plowed  it  is  exposed  more  com- 
pletely to  the  action  of  frost,  thus  giving  a  finer  state  of 
pulverization.  This  is  often  an  advantage  with  heavy 
soils,  but  in  light  soils  it  may  actually  be  a  disadvantage. 
Also,  when  a  cover  crop  is  to  be  turned  under,  there  is 
more  time  for  decomposition  when  turned  under  in  the  fall. 

When  the  soil  is  infested  with  the  larvae  of  injurious 
insects,  fall  plowing  just  as  freezing  weather  begins  will 
often  destroy  many  of  these.  For  early  planted  crops 
there  is  not  always  enough  time  for  proper  preparation  of 
all  the  land  in  the  spring,  and  it  is  good  farm  management 
to  do  part  of  the  plowing  in  the  fall. 

Early  spring  plowing  for  corn,  compared  with  late 
spring  plowing,  has  not  been  the  subject  of  extensive 
investigation.  An  experiment  carried  for  a  single  season 
by  Quiroga,^  at  the  Ohio  State  University,  showed  an 
increase  of  about  7  per  cent  in  the  crop  with  early 
spring  plowing  overlate,  and  a  marked  increase  in  avail- 
able nitrogen  was  found  in  the  early  plowed  land  through- 
out the  season. 

DEPTH     OF     PLOWING 

114.  From  experiment  stations  some  twenty-six  tests 
have  been  reported  on  deep  and  shallow  plowing  for  corn. 
These  results  cannot  be  regarded  as  very  significant  as  a 
guide  in  specific  cases,  since  the  results  were  obtained 
under  a  great  variety  of  conditions.  They  may  be  sum- 
marized as  follows :  — 

Favorable  to  deep  plowing 14 

Favorable  to  shallow  plowing 6 

Indifferent  results 6 


QuiROGA.     Ohio  State  Univ.  BuL,  Series  8,  No.  28. 


164  CORN  CROPS 

There  are  no  experiments  to  show  the  ultimate  effect 
of  following  a  system  of  continuous  shallow  plowing  or 
continuous  deep  plowing,  but  practical  experience  has 
shown  that  land  should  be  occasionally  plowed  deep 
(8  inches)  to  keep  the  surface  in  best  mechanical 
conditions.  Heavy  soil  requires  deep  plowing  more 
often  than  do  light  soils.     Probably  a  very  heavy  soil 


Fig.  42.  —  Plowing  under  alfalfa  sod  in  preparation  for  corn. 

should  be  plowed  deep  once  each  year,  while  certain  light 
soils,  especially  where  rainfall  is  low,  do  very  well  with 
deep  plowing  every  two  or  three  years. 

Hunt  1  summarizes  certain  experiments  with  deep  and 
shallow  plowing  as  shown  on  the  following  page. 

It  has  been  demonstrated  many  times,  that  if  the  soil 
has  been  kept  in  a  good  productive  condition,  that  the 
preparation  immediately  before  planting  or  even  the 
system  of  cultivation  after  planting  is  not  likely  to  have 
an  important  effect  on  the  yield  of  the  current  crop.  The 
crop  secured  does  not  depend  so  much  on  treatment  of 

,1  Hunt,  Thos.  F.     Cereals  in  America,  p.  220. 


PREPARATION  AND  PLANTING 


165 


soil  for  the  present  crop,  so  much  as  the  kind  of  treatment 
it  has  had  for  the  last  ten  or  twenty  years.  The  kind  of 
treatment  to  be  recommended  must  consider  more  the 
future  welfare  of  the  land,  than  present  benefits  to  be 

derived. 

TABLE  XXXVI 

Yield  of  Corn  in  Bushels 


Depth  of 

Plowing 

Station 

Inches 

3 

4 

6 

8 

10 

13 

Illinois 

52.9 

69.4 

69.3 

71.7 

Illinois 

54.0 

57.5 

56.0 

Indiana       (average       3 

41.8 

42.0 

years) 

39.5 

40.5 

42.3 

Pennsylvania    (average 

3  years) 

47.0 

62.0 

57.5 

58.5 

New  Hampshire  ^      .     . 
Alabama 

14.2 
24.1 

26.2 

29.4 

28.2 
24.2 

Minnesota       .... 

65.8 

64.4 

59.52 

Ohio^ 

43.1 

42.9 

Nebraska 

38.5 

31.0 

1  Tons  of  green  silage.     Depths  were  3,  5,  7,  and  9  inches. 

2  Also  subsoiled  6  inches  deeper.  «  Depths  3  and  7  inches. 

So  far  as  tillage  is  concerned,  as  a  factor  in  maintaining 
crop  production,  the  following  principles  may  be  set  forth  : 

That  all  land  should  occasionally  be  plowed  8  to  10 
inches  deep.  On  heavy  land  about  once  a  year,  but  on 
lighter  soil,  and  in  rather  dry  regions,  once  in  two  or  three 
years  being  sufficient. 

The  plowing  should  be  done  when  the  land  is  in  proper 
condition  to  pulverize. 

Quite  thorough  treatment  with  pulverizing  tools,   as 


166  CORN  CROPS 

harrows,  rollers,  and  cultivators,  is  essential  to  keeping  the 
soil  in  good  mechanical  condition. 

SUBSOILING 

115.  The  subsoiler  is  a  tool  for  loosening  the  subsoil 
without  bringing  it  to  the  surface.  While  tools  for  this 
purpose  have  been  in  use  for  many  years  and  have  been 
generally  tried  out  in  all  the  principal  agricultural  regions, 
yet  subsoiling  is  nowhere  in  general  practice.  General 
experience  has  confirmed  results  obtained  at  the  Nebraska 
station,  where,  in  a  cooperative  test  with  fifty-nine  farmers 
for  three  years,  beneficial  results  were  obtained  on  soils 
having  a  heavy  or  impervious  subsoil,  but  on  loam  sub- 
soils the  results  were  indifferent  or  injurious. 

PREPARATION    OF   PLOWED    LAND 

116.  The  amount  of  fitting  that  must  be  given  to  land 
after  plowing  depends  on  the  soil  and  the  seasonal  condi- 
tions. A  good  loam  soil,  plowed  when  in  just  the  proper 
condition,  may  need  very  little  fitting  with  the  simplest 
tools,  as  harrow  and  float,  in  order  to  bring  it  to  a  proper 
mechanical  condition.  On  the  other  hand,  the  same  soil  if 
plowed  when  too  wet,  or  if  when  wet  it  had  been  tramped 
by  stock  in  pasturing,  would  require  more  labor  and  a 
greater  variety  of  tools  for  proper  fitting.  This  emphasizes 
the  importance  of  plowing  only  when  the  soil  is  thoroughly 
pulverized  by  the  plow.  Also,  further  pulverizing  of  the 
soil,  with  harrow  or  cultivator,  is  most  easily  accomplished 
within  twenty-four  hours  or  less  after  plowing,  and  one 
harrowing  at  this  time  may  accomplish  several  times  as 
much  as  a  few  days  later,  when  the  clods  have  dried. 

There  are  certain  heavy  clay  soils  that  always  require  a 


PREPABATION  AND  PLANTING  167 

great  deal  of  fitting  for  good  results.  The  best  tool  for 
pulverizing  to  a  depth  of  several  inches  is  the  disk-harrow 
Where  the  land  is  stony  or  hard,  a  cutaway  is  more  effec- 
tive. On  very  stony  or  rough  land,  a  spring-tooth  is  more 
practicable  than  the  disk,  or  the  ordinary  cultivator  can 
also  be  used  to  good  advantage.  For  surface  finishing,  the 
spike-tooth  harrow  and  weeder  are  used  for  pulverizing 
and  the  board  drag  and  roller  for  further  reduction. 

Re-packing  the  soil  after  deep  plowing  is  an  important 
function  of  all  tillage  in  preparing  the  seed-bed.   When  the 


Fig.  43.  — A  modern  disk-harrow.    A  tool  that  pulverizes  the  surface  and 
packs  the  subsurface  at  one  operation. 

plowing  is  done  long  in  advance,  so  that  heavy  rains  may 
come,  little  attention  need  be  given  to  repacking.  A  fairly 
compact  seed-bed  is  desirable  at  planting  time,  though  not 
so  important  with  corn  as  with  wheat. 

A  good  method  of  repacking  a  loose  seed-bed  is  to  use 
either  a  subsurface  packer,  or  quite  as  well  a  disk-harrow, 
set  straight  (no  angle  to  disks)  and  loaded  with  sufficient 
weight  to  cut  nearly  through  the  furrow  slice.  These 
tools  will  pack  the  bottom  of  the  furrow  slice.     To  pack 


168  CORN   CROPS 

the  surface,  a  roller  or  a  smoothing  harrow,  or  both,  may 
be  used. 

Clearing  of  weeds  is  important  in  preparation.  One 
principal  advantage  of  early  plowing  is  that  more  weeds 
may  be  germinated  and  destroyed  before  planting.  While 
weeds  are  germinating  rapidly,  it  is  often  an  advantage  to 
delay  planting  until  the  land  can  be  entirely  cleared,  as  it  is 
much  easier  to  destroy  weeds  before  planting  than  after- 
ward. 

To  sum  up,  it  is  important  to  plow  the  land  when  in 
just  the  right  tilth  for  plowing,  to  pulverize  thoroughly 
to  repack  when  the  seed-bed  is  loose,  and  to  destroy  weeds 
before  planting. 

PLANTING    THE    SEED 
METHODS 

117.  (1)  The  seed  may  be  "  surface"  planted,  the  land 
being  prepared  level  and  the  seed  planted  in  rows  1  to  3 


Fig.  44.  —  Combined  lister  plow  and  drill. 

inches  below  the  surface.  (2)  The  planter  may  have  a 
furrow  opener,  usually  a  pair  of  disks  which  open  up  a 
shallow  furrow,  the  seed  being  planted  in  the  bottom  of 
this.  (3)  A  lister  may  be  used,  which  is  essentially  a 
double-moldboard  plow  throwing  a  furrow  slice  each  way. 
The  land  is  furrowed  as  deep  as  possible  with  the  lister, 
the  corn  being  planted  in  the  bottom. 


PREPARATION  AND  PLANTING 


169 


Surface  planting  is  the  method  in  common  use  on  all 
heavy  lands  or  in  regions  where  rainfall  is  plentiful,  being 
the  common  method  in  all  the  States  east  of  the  Missouri 
River.     The   "  furrow  opener,"   or  disk  planter,  is  also 


Fig.  45. 


A  combined  lister  and  drill.    The  land  is  not  plowed  in  prep- 
aration for  listing. 


popular  with  many  farmers,  especially  when  it  is  desirable 
to  drill,  as  in  the  growing  of  silage  or  fodder  corn. 

The  lister  came  into  vogue  about  twenty-five  years  ago, 
but  it  is  used  extensively  only  where  the  soils  are  rather 
light  in  texture  (loam  or  sandy  loam)  and  in  regions  of 
rather  low  rainfall.  In  central  Nebraska,  Kansas,  and 
Oklahoma,  one-half  or  moie  of  the  corn  is  listed.     List- 


PEEPARATION  AND  PLANTING  171 

ing  is  not  practicable  on  land  subject  to  washing,  as 
the  planting  is  hkely  to  be  destroyed  by  heavy  rains. 
Also,  in  cold  or  wet  soils  the  seed  is  likely  to  rot  in  the 
lister  furrows,  or  growth  of  the  young  plants  to  be  much 
retarded.  Where  listing  is  practicable,  namely,  in  dry, 
warm  soils,  it  is  a  very  cheap  method  of  producing  corn, 
as  the  ground  is  not  plowed  before  planting,  though  it  is 
usually  disked.     Cultivation  is  simple  and  easy. 

SOWING    CORN    FOR    FORAGE 

118.  For  coarse  forage  or  soiling,  corn  is  frequently  sown 
broadcast  or  drilled  thick  with  a  grain  drill.  One  to  two 
bushels  of  seed  are  sown  per  acre.  Usually  a  rather  small 
early  variety  is  used,  rather  than  a  tall  or  late  variety. 


Fig.  47.  —  Corn  sown  broadcast  for  forage.     In  above  ease  was  sown  after 
wheat  harvest. 


172 


CORN   CROPS 


Early  sweet  com  is  well  adapted  for  this  purpose  and  is 
often  sown  in  July  after  a  small-grain  crop  has  been  har- 
vested. 

CHECKING   AND    DRILLING 

119.  When  corn  is  to  be  surface  planted  it  is  usually 
^'  checked,"  that  is,  planted  in  hills  and  rowed  both  ways, 
thus  permitting  of  cross  cultivation.  When  corn  is  drilled 
on  the  surface,  it  is  often  difficult  to  keep  weeds  out  of  the 


Fig.  48.  — A  two-row  corn  planter.    Will  drop  in  hills,  rowing  both  ways, 
or  in  drills.     Commonly  called  a  check-rower. 

row,  as  little  soil  can  be  thrown  around  the  plants  in 
cultivating.  This  difficulty  is  overcome  in  a  large  measure 
by  using  the  furrow  opener  and  placing  the  corn  in  a 
shallow  furrow. 

TIME    OF   PLANTING 

120.  Many  experiments  have  been  made  on   the   time 
of  planting,  but  the  principal  conclusion  may  be  stated  as 


PREPARATION  AND   PLANTING 


173 


finding  an  average  range  of  about  six  weeks  for  corn 
planting.  The  very  earliest  and  the  very  latest  plantings 
are  usually  not  so  successful  as  those  about  midseason. 
For  example,  the  Illinois  station  in  1890  made  plantings 
from  April  28  to  June  9.     The  average  yield  of  the  corn 


Fig.  49.  — Special  attachments  for  corn  planter  shoes. 

planted  in  May  was  73  bushels  per  acre,  while  the  average 
yield  of  the  three  remaining  plantings,  one  in  April  and 
two  in  June,  was  63  bushels  per  acre. 

Many  experiments  at  other  stations  bear  out  the  state- 
ment that  there  is  a  period  of  about  three  weeks  for  corn 
planting  with  equal  chance  of  success,  though  there  are 
occasional  seasons  when  the  very  early  or  very  late  plant- 
ings are  best.  The  optimum  season  is  shorter  in  the  North 
and  longer  in  the  South. 

TABLE   XXXVII 

Time  of  planting  Corn  in  Certain  Regions  ^ 


Region 

Beginning 

General 

Ending 

Planting 

Period 

Days 

Gulf  States 

Central  States  (Virginia 

to  Kansas)  .... 
Northern    States    (New 

York  to  Minnesota)   . 

March  15 
April  15 
May  10 

April  5 
May  1 
May  20 

May  10 
May  25 
June  1 

55 
40 
20 

1  U.  S.  Dept.  Agr.  Yearbook,  1910,  p.  491. 


174 


CORN   CROPS 


The  above  table  shows  that  the  planting  season  begins 
about  two  months  earlier  in  the  Gulf  States,  as  compared 
with  the  Northern  States,  but  the  total  length  of  the  plant- 
ing season  is  about  three  times  as  long. 

The  average  of  the  beginning  of  corn  planting  is  also 
shown  by  the  accompanying  chart :  — 


MAY/5 


Fig.  50.  —  Chart  showing  average  date  of  planting  corn  in  the  United 

States. 


The  percentage  of  moisture  in  the  crop  at  harvest  time 
usually  increases  with  the  lateness  of  planting,  after  a 
certain  date,  as  illustrated  by  the  following  data  from  the 
Illinois  station  :  ^  — 

1  111.  Agr.  Exp.  Sta.,  Bui.  20.     1892. 


PREPARATION  AND  PLANTING 


175 


TABLE  XXXVIII 
Data  taken  at  Husking  Time 


Pounds  to 

Percentage 

Bushels  of 

Bushels  op 

Date  of 

MAKE  One 

OF  Moisture 

Air-dry 

rLANTING 

Bushel  in 

IN  Sheli-ed 

Dry  Corn 

Corn 

Acre 

April  25  .     . 

69.9 

14.0 

52.6 

50.8 

May  2     .     . 

70.8 

14.6 

52.6 

50.4 

May  9     .     . 

70.9 

14.8 

50.7 

48.5 

May  16  .     . 

74.4 

17.0 

53.3 

49.7 

May  23  .     . 

80.0 

19.3 

57.9 

34.1 

May  30  .     . 

96.8 

24.0 

40.0 

37.5 

June  8     .     . 

97.9 

23.9 

43.9 

37.5 

June  13  .     . 

127.8 

31.5 

25.2 

19.4 

DEPTH    OF    PLANTING 

121.  Corn  is  usually  planted  1  to  4  inches  deep.  Re- 
sults from  several  experiment  stations  are  summarized  as 
follows :  — 

TABLE  XXXIX 
Planting  Corn  at  Different  Depths 


Yield  per  Acre  in  Bushels 

Depth  op 

Planting 
Inches 

OhiQl 

Average 
6  Years 

Indiana  2 
Average 
6  Yeara 

Illinois' 
Average 
5  Years 

1 

56.6 

38.6 

78.0 

2 

51.2 

39.2 

72.0 

3 

46.8 

37.8 

65.0 

4 

28.8 

69.0 

5 

61.0 

6 

60.0 

1  Ohio  Agr.  Exp.  Sta.,  Rpt.  1890:  87. 

2  Ind.  Agr.  Exp.  Sta.,  Bui.  64:  5.     1897. 

3  111.  Agr.  Exp.  Sta.,  Bui.  31:  353. 


176 


CORN   CROPS 


In  no  case  has  the  average  yield  been  increased  by  plant- 
ing more  than  2  inches  deep.  In  heavy  soils,  such  as  of 
the  Ohio  station,  shallow  planting  was  decidedly  better, 
while  in  loose  loam  soil,  at  the  Illinois  station,  the  depth  of 
planting  did  not  vary  results  so  much.  Also,  when  the 
soil  is  warm  and  dry  the  corn  should  be  planted  deeper 
than  when  the  soil  is  cold.  In  two  years  out  of  seven  at 
the  Ohio  station,  when  the  soil  was  drier  than  common,  the 
3-inch  plantings  gave  the  best  results. 

Some  persons  have  thought  that  deep  planting  would 
establish  the  roots  deeper  in  the  soil.  It  has  been  found, 
however,  that  the  roots  spread  out  at  about  the  same  depth, 
no  matter  what  the  depth  of  planting.  Ordinarily  the 
roots  spread  out  about  1  inch  below  the  surface. 

It  would  seem,  then,  there  is  no  object  in  planting  corn 
deeper  than  is  necessary  to  insure  plenty  of  moisture  for 
good  germination. 

RATE    OF   PLANTING 

122.  The  customary  rate  of  planting  varies  with  soils 
and  climate.  In  the  South  the  corn  rows  are  often  5  feet 
apart  and  the  hills  4  feet  apart,  with  two  stalks  to  a  hill. 
The  rate  of  planting  increases  toward  the  North.  Cus- 
tomary rates  are  as  follows  :  — 

TABLE  XL 


Region 


Gulf  States 

Middle    States    (Virginia    to 

Kansas) 

Northern  States    (New  York 

to  Minnesota) 


Distance  Apart 
OF  Hills 

Plants 
PER  Hill 

4' +  5' 

2 

3'8"  +  3'8" 

2-3 

3'6"  +  3'6" 

3-4 

Plants 
PER  Acre 


4,000 

9,000 

12,000 


PREPABATION  AND  PLANTING 


177 


The  rate  of  planting  is  partly  regulated  by  the  size  of 
plant.  Plants  in  the  Gulf  States  are  about  twice  as  large 
as  in  the  Northern  States,  due  in  part  to  climate  and  also 
to  the  longer  growing  season. 

It  has  been  shown,  however,  that  for  a  given  place  the 
rate  of  seeding  within  wide  limits  does  not  have  a  marked 
effect  on  yield.  An  experiment  regarding  this  point  was 
conducted  by  the  Illinois  Agricultural  Experiment  Station. ^ 


Fig.  51.— a  Southern  method  of  phmting  on  poor  soils.  Rows  wide 
apart,  and  a  crop  of  peanuts  between.  For  soil  improvement  cowpeas 
are  sometimes  grown  between. 


For  three  years  corn  was  planted  at  rates  varying  from 
5,940  to  47,520  kernels  per  acre.  The  maximum  yield 
was  obtained  with  11,573  kernels  per  acre,  though  almost 
as  good  yields  resulted  when  15,840  or  23,760  kernels  were 

1  111.  Agr.  Exp.  Sta.,  Bui.  13  :  410. 


178 


CORN   CROPS 


planted.     The  average  yields  were  81,  77,  and  76  bushels 
per  acre,  respectively. 

At  the  Nebraska  station,  corn  was  planted  in  hills  3 
feet  8  inches  apart  each  way,  the  stand  varying  from  one 
to  five  plants  per  hill. 

TABLE  XLI 

Average  Results  from  planting  Corn  at  Various  Rates 
FOR  Six  Years  (1903-1908),  Nebraska  Station  ^ 


Plants 
PER  Hill 

Yield 
PER  Acre 
Bushels 

Average 
Weight 
OF  Ear 
Ounces 

Number 

OF  Ears 

per  100 

Plants 

Number  of 
Tillers  per 
100  Plants 

Two- 
Eared 
Plants 
PER  100 

Barren 
Plants 
PER  100 

1 
2 
3 
4 

5 

48.3 
67.7 
75.5 
76.7 
76.3 

10.5 

10.6 

9.4 

8.2 
7.4 

161 

115 

95 

82 

77 

138 

60 

25 

10 

3 

13.32 

4.9 

2.4 

.8 

1.1 

3.0 

4.8 

6.9 

8.3 

10.8 

1  Nebr.  Agr.  Exp.  Sta.,  Bui.  112  :  30.     1909. 

2  Four  years  only. 

There  was  practically  no  difference  in  yield  when  three, 
four,  or  five  plants  were  grown  to  the  hill. 


ADJUSTMENT    OF    CORN    PLANTS 

123.  As  the  number  of  plants  increased,  the  size  of  ear 
and  the  number  of  ears  decreased,  while  the  number  of 
barren  plants  increased.  One  stalk  per  hill  produced  64 
per  cent  and  two  stalks  per  hill  90  per  cent  as  much  grain 
as  did  three  stalks  per  hill,  due  principally  to  the  increased 
size  of  ear  and  number  of  tillers  producing  ears  and  to  the 
decrease  in  number  of  barren  plants.  It  is  evident  that 
the  corn  plant  is  capable  of  a  wide  range  of  adjustment 


PREPARATION  AND  PLANTING 


179 


ECONOMIC   VALUE    OF   TILLERS 

124.  The  question  often  arises  as  to  whether  tillers 
should  be  pulled  when  they  appear  in  abundance.  Data 
were  taken  at  the  Nebraska  station  for  five  years,  and  in 
every  case  the  yield  was  decreased  by  removing  tillers. 
For  three  years  the  corn  was  planted  at  different  rates,  the 
data  being  summarized  as  follows  :  — 

TABLE  XLII 

Effect  on  Yield  of  Grain  of  removing  Tillers  from  Corn 
Three- Year  Average  (1906-1908) 


Tillers  appear  to  develop  in  response  to  the  needs  of  the 
crop,  in  an  attempt  to  luring  the  stand  up  to  normal. 
When  the  stand  is  maximum,  few  tillers  develop.  The 
occasions  are  certainly  very  rare  when  it  would  pay  to 
remove  tillers. 


OTHER    FACTORS   AFFECTING    PRODUCTION    OF   TILLERS 

125.  On  some  soils  tillers  do  not  develop  even  when  the 
planting  is  thin.     When  early  growth  is  slow  or  retarded, 


180 


CORN  CROPS 


as  on  heavy  or  cold  clay  soils,  there  is  not  sufficient  stimu- 
lus early  in  the  life  of  the  plant  to  start  the  tillers. 

KATE    OF   PLANTING    ON    DIFFERENT   SOILS 

126.  On  good  soils  it  is  generally  recognized  that  plant- 
ing should  be  thicker  than  on  poor  soils.  This  is  shown  by 
data  obtained  by  the  Illinois  station.^  In  a  series  of  tests 
on  different  soils,  corn  was  planted  in  hills  at  various  dis- 
tances apart  and  two  or  three  stalks  per  hill.  Grouping 
the  data  so  as  to  include  all  fields  yielding  more  than  50 
bushels  per  acre  in  one  class,  and  all  yielding  less  than  50 
bushels  in  the  other  class,  the  following  results  are  obtained : 

TABLE   XLIII 

Rate  of  Planting  and  Yield  on   Soils   producing  More   or 
Less  than  50  Bushels  per  Acre 


More  than  50 
Bushels  per  Acre 

Less  than  50 
Bushels  per  Acre 

Region 

Two 
Kernels 
per  Hill 

Three 
Kernels 
per  Hill 

Two 
Kernels 
per  Hill 

Three 
Kernels 
per  Hill 

Northern  Illinois  .     .     . 
Central  Illinois 

57.9 

59.8 

68.5 

62.8 

41.4 
43.2 

42.4 
40.9 

Average     .... 

58.8 

65.6 

42.3 

41.6 

On  productive  soil  the  yield  was  increased  by  the  thicker 
planting;  but  on  the  poorer  soil  two  kernels  per  hill 
evidently  furnished  the  maximum  stand,  as  no  further 
increase  was  secured  by  three  kernels  per  hill.  Data 
from  the  Indiana  station  show  that  in  dry  seasons  the 

1  III.  Agr.  Exp.  Sta.,  Bui.  126:  366-377.     1908. 


PREPARATION  AND  PLANTING 


181 


thin  plantings  give  the  best  results,  while  in  favorable 
seasons  the  reverse  is  true  :  ^  — 


TABLE  XLIV 

Effect  of  Season  on  Yield  and  Percentage  of  Grain 


Stalks 

Seasonable, 
1888-1891 

Ears 

Dry,  1893-1894 

Ears 

Inches 

Per- 
centage 

Per- 

Apart 

centage 

Bushels 

Pounds 

Bushels 

Pounds 

Corn 

Stalks 

Corn 

Stalks 

191 

49.76 

3,617 

49.1 

22.07 

3,092 

33.3 

16 

54.05 

4,065 

48.2 

21.27 

3,143 

32.2 

14 

57.79 

4,158 

49.3 

19.39 

3,762 

26.5 

15 

57.81 

4,201 

49.6 

14.28 

5,204 

16.1 

11 

59.14 

4,960 

45.5 

13.80 

4,360 

18.1 

This  also  indicates  that  in  semiarid  regions,  as  central 
Nebraska  or  Kansas,  the  regular  practice  should  be  rather 
thin  planting. 

METHOD    OF   DISTRIBUTION    OF   PLANTS 

127.  At  the  Illinois  station,  hill  planting  was  compared 
with  drill  planting  at  various  rates  per  acre.  For  example, 
four  plants  would  be  planted  in  hills  every  48  inches,  in 
comparison  with  two  plants  every  24  inches  or  1  plant 
every  12  inches.  The  conclusion  was  that  it  made  no 
difference  in  what  manner  the  seed  was  distributed,  so 
that  approximately  the  same  number  of  plants  per  acre 
were  grown  in  each  case. 

At  the  Nebraska  station,  a  uniform  distribution  of 
three  grains  per  hill  was  compared  with  distributing  the 

1  Ind.  Agr.  Exp.  Sta.,  Bui.  64  :  4. 


182 


COBN   CHOPS 


seed  in  different  amounts  per  hill  but  planting  the  same 
number  per  acre.  The  uniform  distribution  had  a  slight 
advantage,  but  not  enough  to  indicate  that  the  ordinary 
variation  in  dropping  in  corn  planters  would  materially 
affect  the  yield. ^ 

WIDTH   OF   ROWS 

128.  Width  of  rows  is  an  important  consideration, 
since  the  amount  of  labor  required  in  planting  and  cul- 
tivating an  acre  is  directly  related  therewith. 

TABLE  XLV 


Distance 

Apart  of 

Rows 

Feet 

Rods  of 

Travel  in 

Cultivating 

One  Acre 

Percentage  Increase  in  Labor 

4.0 
3.5 

3.0 

650 
754 

880 

16  per  cent  increase  over  4  feet 
17  per  cent  increase  over  3.5  feet 
35  per  cent  increase  over  4  feet 

Numerous  experiments  have  not  shown  a  practical 
advantage  in  having  rows  closer  than  36  inches  in  the 
northern  hmit  of  corn-growing  States,  42  inches  in  the 
central  corn  States,  and  48  inches  in  the  Southern  States, 
when  the  standard  type  of  corn  for  the  region  is  grown 
primarily  for  grain.  A  small  early  variety  may  be 
planted  closer. 

When  the  corn  is  grown  primarily  for  silage  or  fodder; 
somewhat  closer  planting  will  give  a  greater  yield  of 
forage. 

1  Nebr.  Agr.  Exp.  Sta.,  Bui.  11£  :  35. 


PREPARATION  AND  PLANTING 


183 


YIELD    OF   FORAGE 

129.  When    yield    of    forage    is    considered,    numerous 

experiments  have  shown  that  the  yield  of  forage  increases 

with  the  rate  of  planting  up  to  a  point  about  twice  that 

required   for   maximum   yield   of   grain.     The   following 

data  illustrate :  — 

TABLE  XLVI 

Yield  of  Grain  and  Stover  when  Corn  was  planted  at 
Different  Rates,  Three-year  Average.  Rows  3  Feet 
8  Inches  Apart.     Illinois  Station^ 


Rate  of  Planting 

Kernels  per  Acre 

Bushels  of 

Shelled  Corn 

PER  Acre 

Tons  of  Stover 
PER  Acre 

Ratio  op 

Shelled  Corn 

to  Stover 

5,940 

55 

2.5 

100 :  16  ) 

9,504 

72 

2.9 

100 

140 

11,880 

81 

3.0 

100 

130 

15,840 

77 

3.1 

100 

140 

23,760 

76 

3.7 

100 

174 

47,520 

59 

4.8 

100 

290 

111.  Agr.  Exp.  Sta.,  Bui.  13  :  410. 


EFFECT   ON   COMPOSITION 

130.  The  principal  effect  on  composition  when  the  rate 
of  planting  is  increased  is  the  change  in  ratio  between 
percentage  of  ear  and  stalk.  By  referring  to  Table  XLVI, 
last  column,  it  will  be  seen  that  the  proportion  of  stalk  to 
ear  increases  as  the  rate  of  planting  increases,  there  being 
more  than  twice  the  proportion  of  stover  with  the  thickest 
planting  as  compared  with  the  minimum  ratio  (11,880 
kernels).  The  comparative  analysis  of  stover  and  grain 
as  summarized  by  Jenkins  and  Winton  is  given  in  the 
following  table :  — 


184 


CORN   CROPS 


TABLE  XLVII 

Composition   of    Stover  and    Grain    in 

Basis 


Corn.     Water-free 


Nitro- 

Number 

Ash 

Protein 

Fiber 

gen-free 

Fat 

OF 

Per- 

Per- 

Per- 

Extract 

Per- 

Analysis 

centage 

centage 

centage 

Per- 
centage 

centage 

Fodder  .     .     . 

35 

4.7 

7.8 

24.7 

60.1 

2.8 

Leaves  . 

17 

7.9 

8.6 

30.6 

51.0 

1.9 

Husks    .     .     . 

16 

3.5 

5.0 

32.2 

57.9 

1.4 

Stalks    .     .     . 

15 

3.6 

5.9 

34.8 

64.1 

1.6 

Stover    .     .     . 

60 

5.7 

6.4 

33.0 

53.2 

1.7 

Grain     .     .     . 

208 

1.7 

11.7 

2.4 

78.1 

6.1 

In  well-developed  corn  planted  at  proper  distance  for 
maximum  yield,  the  weight  of  shelled  corn  will  be  almost 
equal  to  the  weight  of  stalk.  Increasing  the  rate  of 
planting  has  very  little  effect  on  the  composition  of  either 
grain  or  stalk,  but,  as  the  proportion  of  stalk  to  grain 
increases,  it  is  evident  that  the  analysis  of  the  whole 
plant  will  show  a  decreased  percentage  of  protein  and  fat 
and  an  increased  percentage  of  fiber.  The  total  protein 
per  acre,  however,  will  increase.  Silage  from  very  thickly 
planted  corn  will  not  be  so  rich  in  percentage  of  protein 
and  fat,  but  the  total  yield  per  acre  will  be  greater. 

By  reference  to  Table  XLIV  it  will  be  seen  that  the  rate 
of  planting  has  more  effect  on  percentage  of  ears  in  a  dry 
season  than  in  a  seasonable  year.  The  same  would  be  true 
on  poor  soil. 

CHOICE    OF   A   VARIETY 

131.  There  are  probably  one  thousand  named  varieties 
of  corn.     This  very  large  number  of  varieties,  many  of 

1  U.  S.  Dept.  Agr.,  Office  Exp.  Sta.,  Bui.  77.     1892. 


PREPARATIOX  AND   PLANTING  185 

which  are  of  onl}^  local  importance,  makes  rather  confusing 
a  stud}^  of  experiments,  in  order  to  select  the  best  varieties. 
In  some  cases  a  number  of  varieties  have  had  a  common 
origin  and  for  a  general  discussion  might  be  grouped  to- 


FiG.  52.  —  Rough  division  of  the  United  States  into  corn  regions,  accord- 
ing to  the  types  of  corn  grown. 

gether.  There  are  other  groups,  originating  from  widely 
different  sources,  which  are  yet  very  similar  for  all  practi- 
cal purposes. 

The  eastern  half  of  the  United  States,  where  most  of 
the  corn  is  grown,  may  be  roughly  divided  into  large 


186  CORN   CROPS 

regions,   within  which   certain  types   and  varieties  pre- 
dominate to  a  greater  or  less  degree. 

Elevation  must  always  be  considered  in  selecting  a  type. 
For  example,  the  coast  plains  of  North  Carolina  would 
probably  require  a  type  similar  to  that  suitable  to  the  Gulf 
States,  while  the  mountain  regions  would  require  a  type 


Y^^  53.  _  Prolific  varieties  of  corn  produce  from  two  to  six  ears  per  stalk. 
They  are  adapted  principally  to  the  cotton  belt.     (Cockes  prolific.) 


PREPARATION  AND   PLANTING  187 

normally  adapted  to  a  region  as  far  north  as  Ohio.  Thus, 
in  North  Carolina,  above  2800  feet,  flint  varieties  are 
recommended  —  the  type  of  corn  most  common  in  the 
New  England  States.  Other  local  considerations  enter 
in,  but  in  general  the  following  varieties  have  been  found 
satisfactory  in  the  regions  indicated  :  — 

Natural  divisions 

Section  No.  1.  Gulf  States.  Prolific  varieties  bearing 
160  to  200  ears  to  100  stalks,  on  the  average,  give  better 
results  than  those  bearing  only  single  ears.  Among 
the  best  of  these  are :  — 

Mosby  Sanders  Albemarle 

Cocke's  Prohfic  Blount  Marlboro 

Large-eared  varieties  are  :  — 
St.  Charles  White  Boone  County  White 

Section  No.  2.  In  this  region  large  single-ear  varieties 
share  about  equal  importance  with  prolific  varieties. 
In  addition  to  the  prolific  varieties  named  a})ove,  we  find 
such  varieties  succeeding  as  :  — ■ 

For  good  fertile  land  :  — 

Boone  County  White  St.  Charles  White 

Huffman  White  Pearl 

Leaming  Hickory  King 

For  poorer  soils  and  upland  :  — 

Hickory  King  Sanders 

Leaming  St.    Charles    White    (Early 

Strains) 
For  high  elevations  :  — 

Eight-row  Flint 


188 


CORN   CROPS 


This  region  partakes  about  half  and  half  of  the  varieties 
common  to  the  regions  north  and  south  of  it. 

Section  No.  3.  This  is  the  ''  Corn  Belt."  Only  large 
single-ear  dent  varieties  are  grown.  South  of  this  belt 
the  dent  corn  is  mostly  white  in  color,  but  in  the  Corn 
Belt  yellow  corn  is  as  popular  as  white.  The  leading 
varieties  are :  — 


Yellow 
Leaming 
Ried's       Yellow 

Dent 
Riley's  Favorite 
Legal  Tender 


White 
Silver  Mine 
Boone        County 

White 
Johnson     County 

White 
St.  Charles  White 


Early  varieties 
Pride    of    the 

North 
Early  Calico 
White  Cap 


Leaming  is  probably  the  most  extensively  cultivated 
corn  in  the  United  States,  being  not  only  a  universal 
favorite  as  a  field  corn,  but  also  grown  extensively  for 
silage  corn.  Silver  Mine  is  probably  second  in  impor- 
tance. 

Section  No.  4.  This  is  more  of  the  nature  of  a  small- 
grain  region,  but  corn  culture  is  increasing.  A  few  years 
ago  flint  corns  predominated,  but  in  recent  years  early 
dent  corns  have  been  developed  and  have  largely  replaced 
the  flints. 


Dent  varieties 
Pride  of  the  North 
Minnesota  No.  13 
Wisconsin  No.  7 
Early  Huron 
White  Cap 

Section   No.    5.     Flint    corns    are    grown    principally, 
though  on  the  best  soils  below  1000  feet  elevation.     The 


Flint  varieties 
King  Philip 
Smut  Nose 
Eight-row  Yellow 
Hall's  Gold  Nugget 


PREPARATION  AND  PLANTING 


189 


early  dent  varieties  share  about  equal  popularity  with 
the  flints.  Above  1000  feet  elevation,  flints  are  almost 
universal. 


Flint  varieties 
Eight-row  and  Twelve-row 

Yellow  Flint 
King  Philip 
Canada  Smut  Nose 


Dent  varieties 
Pride  of  the  North 
White  Cap 
Hall's  Gold  Nugget 
Various     acclimated 
varieties 


local 


In  this  section,  one-third  to  one-half  of  the  corn  is 
grown  for  silage.     For  this  purpose  the  seed  is  usually 


Fig.  54.  —  Four  ears  in  center  are  Sanford  white  flint,  the  longest  type  of 
cultivated  corn.  On  right  and  left  are  shown  typical  ears  of  dent  and 
flint,  for  comparison. 


190  CORN  CROPS 

purchased  and  large  varieties,  are  used  that  do  not  ripen 
grain  but  are  barely  mature  enough  for  silage  when  frost 
comes.  Leaming  is  the  favorite  with  Hickory  King, 
Eureka  Ensilage,  Burrill  and  Whitman,  and  Evergreen 
Sweet  following.  In  fact,  almost  all  the  large  dent 
varieties  are  used  to  some  extent  for  ensilage  on  the  lower 
elevations,  while  flints  are  grown  on  the  higher  lands. 

The  importance  of  using  acclimated  seed  has  already 
been  pointed  out  (page  117).  Acclimated  native  seed 
should  always  be  used  for  grain  growing;  and  even  for 
ensilage,  while  it  is  not  necessary  that  the  grain  should 
mature,  a  better  quality  of  silage  is  secured  if  the  climatic 
change  is  not  too  great. 

PREPARING   SEED    FOR   PLANTING 

132.  In  the  more  humid  part  of  the  Corn  Belt,  corn  is 
very  likely  to  decrease  in  germination.  This  necessitates 
some  precautions  in  curing  the  seed  corn.  In  regions 
where  the  fall  and  winter  climate  is  clear  and  compara- 
tively dry,  there  is  less  difficulty,  but  abnormal  conditions 
occur  often  enough  to  justify  special  care  of  the  seed  corn 
as  a  regular  practice. 

CAUSES   OF   POOR   GERMINATION 

133.  Slow  or  imperfect  drying  of  the  mature  corn, 
often  accompanied  with  freezing,  seems  to  be  the  prin- 
cipal cause  of  deterioration  of  vitality  in  the  germ.  When 
corn  is  first  ^'  ripe  "  the  kernels  will  usually  contain  about 
30  per  cent  moisture.  This  would  be  about  September  15 
to  October  1  in  the  Northern  Central  States.  If  the 
weather  is  dry  and  favorable,  the  grain  should  dry  down 
to  about  20  per  cent  moisture  in  the  course  of  four  to  six 


PREPARATION  AND  PLANTING 


191 


weeks.  If  the  climate  is  fairly  dry,  the  corn  should  then 
remain  in  a  good  germinating  condition  either  on  the 
stalks  or  in  good  dry  storage. 

The  principal  cause  of  loss  in  vitaUty  seems  to  be  failure 
to  dry  out  properly  upon  becoming  ripe.  It  is  not 
necessary  for  the 
corn  to  be  frozen 
to  lose  vitality,  as 
it  deteriorates  at 
ordinary  tempera- 
tures during  the 
three  months  fol- 
lowing maturity  if 
not  fairly  dry.  If 
freezing  occurs,  the 
loss  is  increased. 
A  freezing  tempera- 
ture occurring  when 
the  grain  still  con- 
tains a  high  per- 
centage of  moisture 
may  practically  de- 
stroy vitality. 

Any  cause  that 
delays  the  proper 
drying  of  the  corn 
after  maturity  will 
result  in  poor  seed 
corn.  In  many 
cases,  growers  are  using  varieties  too  late  in  maturing  or 
not  well  acclimated.  Deep-kerneled  types  are  more 
likely  to  lose  in  vitality  than  shallow-kerneled  corn. 
Varieties  with  large,  sappy  cobs  are  always  slow  in  drying. 


Fig.  55. — Corn  kernel  split  to  show  germ, 
which  is  the  dark-colored  body  within  the 
white,  and  extending  nearly  the  length  of 
the  kernel.  The  main  outer  part  of  the 
germ  is  the  Scutdlum,  secretes  an  enzyme 
that  reduces  the  starch  for  use  of  young 
plant.  The  column-like  body  in  the  upper 
half  is  the  Phmiula,  develops  into  young 
plant.  The  body  at  the  lowest  point  is  the 
Radicle,  or  root  of  young  plant. 


192  CORN  CROPS 

STORING   SEED   CORN 

To  insure  good  seed  corn,  the  ears  should  be  collected 
as  soon  as  mature  and  dried.  Methods  of  drying  are 
discussed  elsewhere. 

GERMINATION   TESTS 

134.  If  seed  corn  has  been  properly  saved,  there  will 
be  no  occasion  for  making  germination  tests.  It  is  much 
cheaper  to  save  the  seed  properly  than  to  make  germina- 
tion tests.  Whenever  seed  is  to  be  selected  from  a  supply, 
the  quality  of  which  is  doubtful,  careful  germination  tests 
should  be  made. 

The  general  test 

135.  A  general  test  should  be  made  first.  Choose  100 
ears  at  random  and  remove  three  kernels  from  each  at 
different  parts  of  the  ear,  as  butt,  tip,  and  middle. 

A  good  germinater  is  made  by  using  two  pie  tins  or 
dinner  plates.     Fill  one  with  sand,  sawdust,  or  soil.     Place 


Fig.  56.  — A  simple  germinater  for  testing  seed  corn.    The  corn  is  placed 
between  damp  cloths  or  blotters. 

a  cloth  on  this  and  spread  out  the  kernels  to  be  germinated. 
Place  a  second  cloth  over  the  seeds  and  wet  down.  Then 
invert  the  second  pie  tin  or  dinner  plate  over  the  first 
so  as  to  make  a  moist  chamber  within.  Keep  moist  and 
in  a  warm  place.  Six  days  is  sufiiciePf,  time  to  allow  for 
germination.  If  90  per  cent  or  more  oi  the  seeds  show 
good  strong  sprouts,  it  is  doubtful  if  it  would  pay  to  make 
a  germination  test  of  each  ear  separately. 


PREPARATION  AND  PLANTING 


193 


The  ear  test 

136.  When  the  preliminary  test  shows  germination  to  be 
low  or  a  high  percentage  weak,  it  will  pay  to  germinate 
each  ear  separately. 

There  are  several  "  seed  testers  "  on  the  market  adapted 
for  this  work,  but  satisfactory  germinaters  can  be  made 


Fig.  57.  —  Making  a  germination  test.     The  rack  contains  100  ears,  cor- 
responding in  number  to  the  squares  in  the  germination  box. 


at  home.  Usually  a  series  of  shallow  trays  are  made  and 
filled  with  sawdust  or  sand.  A  cloth  is  laid  on  top 
marked  off  in  two-inch  squares,  and  each  square  is  num- 
bered. Twenty  inches  square  is  a  convenient  size,  though 
some  prefer  a  tray  twice  to  five  times  as  large.  The  ears 
to  be  tested  are  laid  out  on  shelves  in  sets  of  ten.  The 
ears  are  then  taken  in  order,  six  grains  removed,  and  these 
grains  placed  in  the  corresponding  square  on  the  cloth. 


194 


COEN  CROPS 


It  is  well  to  take  two  kernels  from  the  butt,  two  from  the 
middle,  and  two  from  the  tip,  of  the  ear.  When  a  tray 
has  been  filled,  the  grains  are  covered  with  a  second 
cloth  and  a  little  sawdust  on  top  and  thoroughly  wet  down. 
When  all  trays  are  filled  they  are  stacked  up  m  a  warm 
place  and  wet  once  a  day  for  five  or  six. days.  All  ears 
that  have  not  shown  a  strong  germination  by  this  time 
should  be  discarded. 


IMPORTANCE    OF    STRONG   VITALITY 

137.  It  should  be  emphasized  that  only  ears  showing  a 
strong,  quick-growing  germ  should  be  used.  C  P.  Hartley 
records    a    typical    experim'ent    illustrating    this    point.^ 


^:~  If-^l^^r- 


Fig.  58.  —  Difference  in  germination   of   ears.     In  each   square  are  six 
kernels,  each  from  a  different  ear. 

1  Hartley,  C.  P.     The  Seed  Corn  Situation.     U.  S.  Dept.  Agr.,  Bur. 
Plant  Indus.,  Giro.  No.  95.     1912. 


PREPARATION  AND  PLANTING 


195 


In  November  two  bushels  of  seed  corn  were  selected,  one 
bushel  being  placed  in  a  corn  crib  and  the  other  in  a  dry 
seed  room.  Germination  was  about  equally  good  in  both 
cases,  but  the  plants  from  the  seed  kept  in  the  dry  house 
were  stronger  and  the  yield  averaged  five  bushels  more 
per  acre. 

GRADING    SEED 

138.  The  corn  planter  cannot  be  adjusted  to  uniform 
dropping  of  seed  unless  the  kernels  are  uniform  in  size. 


Fig.  59.— Three  rows  on  left  from  single  ear  of  good  seed  corn.    Three 
rows  on  right  from  single  car  of  poor  seed  corn. 

Some  growers  sort  the  seed  ears  into  two  or  three  lots, 
according  to  size  of  kernel.  In  some  cases  "  sorters  " 
are  used,  consisting  essentially  of  a  pair  of  screens  that 
take  out  both  the  extra  large  and  the  extra  small  kernels. 

CALIBRATING   THE    PLANTER 

139.  The  dropping  devices  on  planters  are  of  three  types, 
known  respectively  as  (1)  round  hole  drop,  (2)  round  hole 


196  CORN   CROPS 

accumulative,  and  (3)  edge  drop  accumulative.  The 
first  type  represents  the  earliest  type  of  dropper  plate, 
when  it  was  attempted  to  regulate  the  number  of  kernels 
per  hill  by  the  size  of  hole  in  the  dropper  plate ;  the  hole 
being  large  enough  to  take  two,  three,  or  four  grains 
at  a  time.     In  both  the  accumulative  drop  forms,  the  hole 


Edge  Drop  Flat  Drop 

Fig.  60.  —  Two  types  of  planter  plates  for  dent  corn.  The  edge  drop  is 
considered  best  where  the  corn  is  sorted  to  uniform  size,  and  flat  drop 
where  the  seed  is  not  uniform. 

is  large  enough  to  take  only  one  kernel  at  a  time,  the 
desired  number  of  kernels  being  accumulated  one  at  a  time 
in  a  pocket  and  then  dropped.  The  latter  method  is 
considered  more  nearly  accurate  when  the  seed  has  been 
well  sorted.  Before  starting  to  plant,  care  sould  be 
taken  to  see  that  the  dropper-plate  holes  are  of  the  right 
size  for  the  seed  used. 


CHAPTER  XVII 
THE  PRINCIPLES  OF  INTERCULTURE 

TILLAGE   MACHINERY 

A  GREAT  variety  of  tools  has  been  developed  especially 
adapted  for  the  tillage  of  corn.  For  the  first  cultivation 
of  drilled  or  checked  corn,  the  common  smoothing  harrow 
is  often  used.     It  is  an  excellent  tool  for  this  purpose  as 


p,<,    61.  -The  weeder.    A  very  useful  tool  on  loose  soil  for  cultivating 
corn  the  first  four  weeks.    Cultivates  three  rows  at  a  time. 

it  works  a  wide  swath  and  kills  young  weeds  effectively. 
One  disadvantage  is  that  it  carries  considerable  trash  es- 
pecially where  there  are  many  large  com  stubbs  m  the 
land  In  this  case  the  weeder  is  much  better  than  the 
spike  tooth  harrow,  as  it  clears  of  trash  and  does  less  in- 
jury to  the  young  plants.  When  the  weather  is  dry  and 
•'  197 


198 


CORN'  CROPS 


the  plants  tough,  a  weeder  may  be  used  until  the  corn  has 
reached  the  height  of  twelve  inches. 


Fig.  62. 


The  simplest   type'   oi   one-row  cultivator,  in  extensive   use 
throughout  the  corn  belt. 


The  corn  cultivator  has  undergone  a  rapid  evolution  in 
the  past  fifty  years.     The  first  horse  cultivators  were  single 


Fig.  63.  — A  modern  riding  corn  cultivator,  with  handy  adjustments  and 
attachments,  to  readily  adapt  for  all  kinds  of  corn  cultivation.  Disk 
gangs  attached. 


THE  PRINCIPLES   OF  INTEECULTURE 


199 


shovel  plows,  consisting  of  a  very  broad  mold-board 
shovel  mounted  on  a  beam,  with  handles  to  guide.  Later 
two  narrower  shovels  were  substituted  for  the  single  broad 
shovel.  Though  this  was  an  improvement,  it  was  still  nec- 
essary to  go  twice  in  each  row  for  thorough  cultivation. 


Fig.  64.  —  Spring-tooth  attachment. 


Fig.  65.  — Shovel  attachment. 


Fig.    66.  —  Cut    showing 
angle  and  tilt  adjustments. 


Later  two  of  these  double  shovel  plows  were  rigged  on  a  two 
wheel  sulky,  thus  enabling  the  operator  with  two  horses 
to  cultivate  both  sides  of  a  row  at  one  time.  The  corn 
cultivator  is  still  built  essentially  on  this  principle  with 


200  CORN  CROPS 

many  types  of  shovels  and  improvements  for  ease  in  con- 
trolling as  illustrated  in  Figs.  63-66. 

Modern  cultivators  may  be   fitted  with  four  to    eight 
shovels,  the  size  of  the  shovels  decreasing  as  the  number  in- 


FiG.  67.  —  Two-row  corn  cultivator  for  three  horses. 

creases.     The  six  or  eight  shovel  type  is  usually  preferred 
where  the  ground  is  in  good  tilth  and  the  weeds  small. 

Where  the  ground  is  hard  and  the  weeds  large,  so  that 
the  land  must  be  plowed  rather  than  cultivated,  the 
large  four  shoveled  type  is  more  effective.  On  stony 
land  the  spring  tooth  gang  is  often  preferred.  Also 
most  standard  riding  cultivators  may  be  fitted  with  disk 
gangs.  Disk  cultivators  do  excellent  work  in  the  hands 
of  a  skilled  operator.     They  are  especially  desirable  when 


201 


202  CORN   CROPS 

the  soil  is  in  poor  physical  condition  and  needs  pulver- 
izing. 

Two-rowed  cultivators  adapted  for  use  with  either  two 
or  three  horses  are  now  in  general  use.  If  two-row  cul- 
tivators are  to  be  used,  the  rows  should  be  straight  and 
uniformly  equal  distances  apart.  With  the  two-row 
cultivator  it  is  not  possible  to  do  as  careful  work  close  to 


Fig.  69.  —  Late  cultivation  of  corn,  with  narrow  tooth  plow. 

the  row  as  when  a  single  row  is  worked  at  a  time.  On 
the  other  hand,  when  the  corn  is  clean  in  the  row  it  may 
do  all  that  is  necessary  in  half  the  time. 

One  horse  cultivators  are  not  used  much  in  corn  cultiva- 
tion, except  occasionally  for  late  cultivation  where  the 
plants  are  too  high  to  straddle. 

For  listed  corn  a  variety  of  tools  has  been  specially 
devised.  A  spike  tooth  harrow  is  often  used  to  level  the 
ridges  slightly  when  the  corn  first  comes  up.  Then  a 
tool  such  as  illustrated  in  Fig.  70  is  sometimes  used  or, 
more  commonly,  a  two-row  tool  of  the  type  illustrated  in 
Fig  71.     The  first  time  over,  the  disk  followers  are  usually 


THE   PRINCIPLES   OF  INTERCULTURE 


203 


set  to  throw  out,  as  shown  on  the  right  of  the  figure,  with 
a  shield  to  protect  the  young  corn  and  a  pair  of  small 


Fig.  70.  — Tool  for  cultivating  listed  corn  the  first 
time  over. 

shovels  to  work  in  the  bottom  of  the  furrow.      Later  the 
disks  may  be  set  wider  apart  and   set  to  throw  toward 


Fig.  71.  — Two-row  listed  corn  cultivator. 


the  corn.      The  shovels  may  be  adjusted    to  suit  con- 
ditions. 


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204 


THE  PRINCIPLES   OF  INTERCULTURE  205 

140.  Jethro  Tull  said,  "  Tillage  is  manure,"  and  this 
axiom  has  been  more  cr  less  accepted  and  inculcated  into 
our  theories  regarding  the  interculture  of  hoed  crops.  In 
the  case  of  small  grain  crops,  which  are  sown  thickly 
enough  to  fully  occupy  the  land,  benefit  has  rarely  been 
derived  from  interculture.  With  crops  which  are  planted 
wide  apart  and  which  never  fully  occupy  the  intervening 
ground,  it  has  been  found  profitable  to  give  sufficient 
interculture  to  prevent  the  growth  of  weeds. 

How  much  more  interculture  may  benefit  the  crop  than 
by  keeping  down  weeds  is  a  debated  question.  Various 
reasons  have  been  advanced  to  account  for  the  benefits 
of  interculture  and  these  may  be  summarized  as  follows : 

To  destroy  weeds. 

To  conserve  moisture. 

To  reduce  run-off  of  rainfall  by  keeping  the  surface 
loose  and  porous. 

To  aerate  the  soil. 

To  increase  availability  of  plant  food. 

The  relative  importance  of  each  of  the  above  functions 
of  interculture  will  vary  according  to  locality  and  season. 
Interculture  to  aerate  the  soil  and  to  free  fertility  may  be 
important  on  certain  heavy  clay  soils  in  a  humid  region, 
but  negligible  on  more  porous  soils  or  in  a  dry  region. 
Where  torrential  rains  occur  during  the  growing  season, 
it  is  important  to  have  the  surface  in  a  porous,  granular 
condition. 

In  general,  however,  the  conservation  of  moisture  and 
the  destruction  of  weeds  are  properly  advanced  as  the 
principal  objects  of  interculture.  Of  all  objects,  the  de- 
struction of  weeds  appears  to  be  paramount.  This  con- 
clusion is  arrived  at  as  the  result  of  numerous  experiments, 
which  have  shown  that  keeping  down  weeds  by  shaving 


206 


CORN  CROPS 


off  has  given  almost  as  good  results  as  when  the  soil  was 
given  good  cultivation. 

METHODS    OF   TILLAGE    COMPARED 

141.  In  the  following  tables  are  shown  the  results  of 
three  of  the  above-mentioned  experiments  under  very 
different  climatic  and  soil  conditions,  namely,  New  Hamp- 
shire, Illinois,  and  Utah.  All  give  the  same  general  con- 
clusion—  that  culture  beyond  the  destruction  of  weeds 
has  not  given  much  increased  yield. 


TABLE  XLVIII 

Results    at   Three    Stations  with    Different   Methods   op 

Cultivating   Corn.      New  Hampshire   Station    (Bul.  71, 
1900) 


Kind  of  Culture 

Yield 
Bushels  per  Acre 

No  culture,  weeds  permitted  to  grow    .     . 

Shallow,  14  times 

Shallow,  5  times  (ordinary  culture) 

Deep,  5  times         

Mulch,  covered  with  swamp  hay 

17.1 
80.6 
79.1 
69.7 
56.1 

Illinois  Station  (Bul.  31,  1894) 


Average  Yield  for 

Kind  of  Culture 

Five  Years 

Bushels  per  Acre 

None,  weeds  scraped  with  a  hoe       .     .     . 

68.3 

Shallow,  about  four  cultivations 

70.3 

Deep,  about  four  cultivations      .... 

66.7 

Shallow,  about  eight  cultivations 

72.8 

Deep,  about  eight  cultivations     .... 

64.5 

None,  weeds  allowed  to  grow       .... 

THE   PRINCIPLES   OF  INTERCULTUKE  207 

Utah  Station  (Bul.  66) 


Kind  of  Culture 

Average  Yield  foe 

Eight  Years 
Bushels  per  Acre 

None,  weeds  pulled  by  hand 

Scuffle  hoe  (scarified) 

Shallow  tillage,  Ij  inch 

Medium  tillage,  2j  inches 

Deep  tillage,  3j  inches 

Mulched  with  soil 

51.8 
58.8 
52.9 
57.3 
57.4 
55.8 

It  has  been  shown  by  numerous  experiments  on  bare 
soils  that  a  mulch  of  straw  or  of  dry  loose  earth  would 
conserve  considerable  moisture.  It  has  also  been  pointed 
out  heretofore  (page  87)  that  the  need  of  water  is  the 
most  common  limiting  factor  in  corn  production.  Rea- 
soning from  this,  it  seems  that  interculture  should  play 
an  important  part  in  conserving  moisture  and  this  increas- 
ing yield,  but  practical  experiments  fail  to  show  such 
increases. 

WATER-LOSS    FROM    FALLOW   SOIL 

142.  For  three  months  (April,  May,  and  June)  the 
prospective  cornfield  is  essentially  a  bare  field,  exposed  to 
wind  and  sunshine ;  and  it  is  to  be  expected  that  early 
plowing  and  maintenance  of  a  soil  mulch  will  conserve 
moisture  during  this  period. 

At  the  Wisconsin  station  adjacent  plots  of  land  were 
plowed  in  early  spring  seven  days  apart.  During  this 
interval  of  seven  days  the  unplowed  plot  lost  1.75  inch 
of  water,  while  the  plowed  plot  had  actually  gained  mois- 
ture in  the  first  4  feet,  probably  due  to  capillary  water 
from   below. 


208  COBN   CROPS 

Widstoe^  states  that  "  Fortier,  working  under  California 
conditions,  determined  that  cultivation  reduced  the  evap- 
oration from  the  soil  surface  over  55  per  cent."  At  the 
Utah  station  similar  experiments  have  shown  that  saving 
of  soil  moisture  by  cultivation  was  63  per  cent  for  a  clay, 
34  per  cent  for  a  coarse  sand,  and  13  per  cent  for  a  clay 
loam. 

EVAPORATION   UNDER   CORN   CROP 

143.  When  the  corn  becomes  large  enough  to  shade  the 
ground,  which  will  be  soon  after  the  time  that  interculture 
begins,  most  of  the  conditions  causing  loss  of  soil  moisture 
in  fallow  soils  will  have  become  to  a  large  degree  ineffec- 
tive. Wind,  the  most  potent  cause  of  soil  drying,  is 
almost  nil  at  the  soil  surface ;  direct  sunshine  is  cut  off, 
the  soil  being  in  shade  part  of  the  time ;  and  humidity  is 
higher.  At  the  Nebraska  station,  jars  of  water  set  in 
wheat  fields  level  with  the  soil  surface  lost  practically  no 
water. 

Another  important  factor  in  preventing  loss  of  soil 
water  by  evaporation  is  the  spread  of  roots  near  the  sur- 
face. (See  page  27.)  If  there  is  no  rain,  practically  all 
water  moving  upward  from  the  subsoil  is  intercepted  by 
these  roots  and  used  by  the  plants.  If  there  is  rain,  the 
surface  moisture  is  soon  reduced  by  the  surface  roots  to 
a  point  where  upward  capillary  movement  is  retarded. 

From  the  above,  it  appears  that  interculture  of  the 
corn  crop  can  do  very  little  toward  conserving  moisture. 

THE    EFFECT    OF   WEEDS 

144.  A  crop  of  weeds  will  not  only  take  out  moisture, 
but  also  consume  available  plant  food.     As  plant  food  in 

1  WiDSTOE,  John  A.     Dry  Farming,  p.  155. 


THE  PBINCIPLES   OF  INTEECULTUBE 


209 


available  form  is  usually  more  limited  than  the  water 
supply,  the  consumption  of  plant  food  by  weeds  may  be 
even  more  injurious  than  the  consumption  of  water.  Only 
when  water  and  fertility  are  far  in  excess  of  the  needs  of  the 
crop  could  weeds  do  no  harm. 

The  effect  of  witch  grass  in  reducing  yield  is  illustrated 
by  data  obtained  at  the  New  Hampshire  station  (Bulletin 
71,  page  55).  Two  plats  of  corn  were  treated  in  the  same 
manner  and  given  good  cultivation  up  to  June  10.  One 
plat  was  hand-hoed  four  times  after  this  date  in  order  to 
destroy  the  witch  grass,  while  this  was  allowed  to  grow 
in  the  other  plat. 

TABLE  XLIX 
Effect  of  Witch  Grass  in  Corn 


Kind  of  Culture 

Pounds  of  Corn 
Stover 

Bushels  of  Shelled 
Corn  per  Acre 

Hoed 

Unhoed 

11,843 

9,188 

81.6 
61.4 

We  may  conclude  that,  for  corn,  the  principal  object 
of  intertillage  is  to  destroy  weeds,  and  after  this  is  accom- 
plished, further  tillage  will  not  pay. 

The  above  does  not  apply  to  small  tilled  crops,  as  vege- 
tables where  the  soil  is  exposed  and  the  roots  do  not  fully 
occupy  the  surface  soil.  Here  conditions  approach  those 
obtaining  on  fallow  soil. 


DEPTH   AND    FREQUENCY    OF   CULTIVATION 

145.  Since  intertillage  in  corn  apparently  serves  no 
important  function  be3^ond  subduing  weeds,  it  is  to  be 
expected  that  no  increase  in  yield  will  result  from  culti- 


210  CORN  CROPS 

vating  more  deeply  or  more  frequently  than  is  necessary 
in  order  to  accomplish  this  purpose. 

In  TableXLVIII  are  shown  results  at  the  New  Hamp- 
shire, Illinois,  and   Utah  stations  with  deep  and  shallow 
tillage.     The  Illinois  ^  results  with  methods  of  cultivation 
may  be  summarized  as  follows  :  — 
TABLE  L 


Kind  of  Cultivation 


Frequent  (4  plats) 
Ordinary  (4  plats) 
Shallow  (4  plats)  . 
Deep  (4  plats) 


Average  Yield 

FOR  Five  Years 

Bushels  per 

Acre 


68.6 
68.5 
71.5 
65.6 


The  principal  injur}^  of  deep  cultivation  is  that  roots 
are  destroyed.  The  depth  to  which  the  soil  can  be 
stirred  without  injury  to  roots  depends  on  the  soil  to  some 
extent.  (See  page  28.)  In  humid  regions  and  clay  soils, 
perhaps  2  inches  is  the  limit ;  in  loose  loam  soils  in  drier 
regions,  the  roots  are  ordinarily  3  inches  below  the  surface  ; 
while  with  listed  corn,  the  cultivation  may  often  be  as 
deep  as  4  inches.  The  roots  are  usually  shallow  next  to 
the  plant  and  deeper  midway  between  rows. 

It  is  doubtful  whether  it  would  be  an  advantage  to  give 
deep  culture,  even  when  it  could  be  done  without  particular 
harm  to  the  roots,  as  illustrated  with  listed  corn  at  the 
Kansas  station.  , 

Roots  of  listed  corn  are  deeper  than  surface  planted 
corn,  and  there  would  be  little  injury  from  deep  culti- 
vation. 

1  III.  Agr.  Exp.  Sta.,  Bui.  31  :  356. 


THE  PRINCIPLES   OF  INTERCULTUBE 


211 


TABLE    LI 

Results  at  Kansas  Station  with  Deep  and  Shallow  Cul- 
ture FOR  Corn.  Average  for  Four  Years  (1892- 
1896).! 


Treatment 


Listed,  deep  culture 

Listed,  shallow  culture        

Surface  planted,  deep  culture      .... 
Surface  planted,  shallow  culture 
Surface  planted,  deep  and  shallow  culture^ 
Surface  planted,  surface  culture  .... 


Average  Yield 
Bushels  per  Acre 


29.7 
29.3 
27.3 
27.0 
28.1 
23.0 


In  Table  XL VII I  are  also  given  results  with  frequency 
of  cultivation.  The  following  data  from  the  Kansas  sta- 
tion further  illustrate  :  ^  — ■ 

TABLE  LII 


Times  Cultivated 

Times  Cultivated 
Two-year 
Average 

Two-year  Average 

Yield  in  Bushels 

PER  Acre 

Three  times  a  week 

17 

24.8 

Twice  a  week     .     ,     .     .     . 

13 

27.2 

Once  a  week 

7 

27.8 

Once  in  two  weeks       ... 

4 

25.2 

Once  in  three  weeks     . 

3 

24.0 

Once  in  four  weeks      .     .     . 

2 

16.9 

We  may  therefore  conclude,  from  the  data  presented, 
that  up  to  the  time  when  corn  shades  the  ground,  and  the 

1  Kansas  Bui.  6'^  .-233. 

2  Deep  first  cultivation  and  shallow  la;ter. 

3  Kans.  Agr.  Exp.  Sta.,  Bui.  45  :  131. 


212  CORN  CROPS 

field  is  comparatively  fallow,  cultivation  conserves  some 
moisture  as  in  any  fallow  soil.  After  the  corn  crop  is 
thoroughly  established  and  a  layer  of  surface  roots  inter- 
cepts capillary  moisture  from  below,  the  principal  service 
of  cultivation  is  to  destroy  weeds.  Weeds  compete  with 
the  plant  for  both  water  and  plant  food. 

GROWING    CORN    FOR   SILAGE 

146.  The  general  discussion  has  thus  far  had  in  view 
the  culture  of  corn  for  grain.  The  recommendations  taken 
as  a  whole  apply  quite  as  well  to  growing  silage  corn. 
It  is  generally  true  that  the  best  quality  of  silage  is  made 
from  corn  grown  under  conditions  for  producing  the 
maximum  grain  crop. 

For  grain  it  is  necessary  that  the  variety  chosen  should 
mature  sound  grain,  but  in  the  case  of  silage  corn  it  need 
not  mature.  In  the  Southern  States,  and  in  practically 
all  the  Corn  Belt  States,  perhaps  the  best  silage  variety 
is  also  the  best  standard  variety  grown  for  grain.  In 
New  England  and  on  higher  elevations  in  all  Northeastern 
States,  the  most  profitable  silage  variety  will  probably 
be  too  late  to  mature.  At  elevations  of  1000  feet  or  more, 
seed  may  be  secured  at  the  same  latitude  but  grown  500 
to  1000  feet  lower  elevation.  The  growing  season  of 
corn  usually  shortens  about  one  day  to  each  100  feet 
increase  of  elevation.  At  lower  elevations  it  will  be  neces- 
sary to  go  200  to  300  miles  south  for  late  seed.  Dent 
corns  are  usually  preferred  for  silage,  Leaming  being 
perhaps  the  most  popular  dent  variety  for  this  purpose. 
At  higher  elevations  very  early  dents,  sweet  corns,  and 
in  some  cases  flint  corns,  are  best. 

As  pointed  out  heretofore  (page  179),  the  total  weight  of 
dry  matter  increases  with  rate  of  planting,  but  the  propor- 


THE  PRINCIPLES   OF  INTERCULTURE  213 

tion  of  ear  decreases.  In  general,  the  best  rate,  yield 
and  quality  both  considered,  is  about  one-fourth  to  one- 
third  thicker  than  would  be  necessary  to  secure  maximum 
yield  of  grain  under  the  same  conditions. 

Drills  are  best  where  the  corn  is  planted  somewhat 
thickly,  as  for  silage.  Even  where  hill  planting  has  been 
found  best  for  grain  growing,  drill  planting  has  usually 
given  slightly  larger  yields  of  stover.  The  difference, 
however,  is  too  small  to  be  of  much  importance,  and  the 
method  to  be  adopted  is  to  be  determined  by  convenience 
in  tillage  and  harvesting.  Where  harvesting  is  by  ma- 
chinery, drill  planting  is  most  convenient;  but  where 
harvesting  is  by  hand,  hills  are  preferred. 


CHAPTER  XVIII 
ANIMAL   AND   INSECT   ENEMIES 

The  corn  crop  is  more  easily  protected  from  its  animal 
and  insect  enemies  than  most  of  the  important  crops. 
Of  those  insects  that  live  on  the  roots  of  corn,  practically 
all  are  effectively  controlled  by  rotation.  At  present  the 
corn  rootworm  and  root-louse  do  considerable  damage 
throughout  the  corn-belt,  wherever  several  corn  crops  are 
grown  in  succession  on  the  same  land. 

Rodents  and  birds  do  some  damage  every  year,  but 
are  only  considered  serious,  where  corn  is  grown  in  small 
areas.  The  corn  ear  worm  is  difficult  to  control,  but  this  in- 
sect seldom  does  serious  damage  except  in  the  Southern 
States. 

BIRDS 

147.  Crows  give  some  trouble  in  regions  where  they  are 
plentiful  and  the  acreage  of  corn  is  comparatively  small. 
They  pull  up  the  plants  for  a  period  of  two  weeks  after 
the  shoots  appear,  in  order  to  get  the  kernels  for  food. 
Scarecrows  or  strings  stretched  with  pieces  of  paper  at- 
tached are  effective  in  small  fields.  Coating  the  seed  with 
coal  tar  is  a  deterrent,  but  not  a  complete  preventive. 
The  treatment  consists  in  dipping  a  paddle  in  hot  coal  tar 
and  stirring  in  the  seed  corn  until  every  seed  is  coated  with 
tar.     The  seed  is  allowed  to  dry  and  is  then  planted. 

RODENTS 

148.  Small  ground  squirrels  of  several  varieties  dig  up 
seed  one  to  two  weeks  after  planting.  The  coal-tar  treatment 

214 


ANIMAL  AND  INSECT  ENEMIES  215 

recommended  for  crows  is  often  effective  as  a  preventive. 
Poison  is  also  used.  The  ordinary  method  of  poisoning 
is  to  soak  a  quantity  of  corn  in  a  strychnine  solution  and 
plant  this  a  few  days  ahead  of  the  regular  planting,  in 
parts  of  the  field  likely  to  be  molested.  Very  often  the 
squirrels  come  mostly  from  adjacent  pastures  or  meadows, 
and  a  few  rows  of  poisoned  corn  planted  next  to  these  will 
be  effective. 

INSECTS 

149.  The  larvae  of  several  insects  are  very  injurious 
to  corn  under  certain  conditions.  These  may  be  grouped 
as  :  (1)  Insects  injurious  to  the  roots.  (2)  Insects  injurious 
to  the  young  plant  above  ground.  (3)  Insects  injurious 
to  some  part  of  the  mature  plant,  as  ear  or  leaf.  (4) 
Insects  that  become  a])undant  in  cornfields  only  when 
corn  follows  corn  year  after  year,  as  the  corn  rootworm. 
The  remedy  for  this  kind  is  rotation  of  corn  with  other 
crops.  (5)  There  is  another  group,  which  injures  corn 
only  when  it  follows  certain  other  crops.  This  includes 
the  wireworm,  which  is  often  injurious  the  first  and  second 
years  after  grass  sod.  The  grubworm  is  most  often  inju- 
rious after  a  clover  sod.  (6)  Certain  migratory  insects, 
as  the  chinch  bug,  army  worm,  and  stalk  borer,  which 
come  in  mostly  from  adjacent  fields.  The  most  important 
of  these  insects  from  an  economic  standpoint  are  here 
given,  together  with  suggestions  for  their  control :  — ■ 

Cutworms 

Cutworms  live  on  various  kinds  of  grasses.  The  moths 
lay  their  eggs  in  late  summer.  These  eggs  soon  hatch 
and  the  partially  grown  larvse  live  over  winter  in  the 
ground.     They  live  on  vegetation  again  the  following  year 


216  COBN  CROPS 

and  pupate  during  May  and  June.  The  larvae  feed  prin- 
cipally during  the  night,  cutting  the  young  plants  off  near 
the  ground.  •  Late  fall  plowing  usually  destroys  many  of 
the  larvae.  Late  planting  will  often  avoid  them,  and 
when  the  regular  planting  is  destroyed  it  is  usually  safe 
to  depend  on  a  late  replanting  to  escape.  Cutworms  are 
poisoned  by  mixing  one  pound  of  paris  green  to  forty 
pounds  of  bran.  When  applied  with  a  drill  the  mass  is 
moistened  and  dried,  so  as  to  cause  the  poison  to  adhere. 
When  applied  by  hand,  a  quart  of  molasses  is  added  to  the 
mixture. 

Gruhworms 

These  are  larvae  of  the  May  beetles,  or  June  bugs. 
The  eggs  are  laid  in  June,  mostly  in  grasslands,  but  more 
or  less  in  all  cultivated  fields,  especially  if  recently  dressed 
with  barnyard  manure.  The  larvae  live  on  decaying 
vegetable  matter  or  roots,  and  often  prove  very  destruc- 
tive in  cornfields. 

No  effective  remedy  has  been  proposed  except  in  regions 
where  listing  is  practiced.  Listed  corn  is  not  injured  so 
much  as  is  surface-planted  corn. 

Wireworms 

These  are  the  larvae  of  the  family  known  as  "  click 
beetles."  The  eggs  are  laid  in  the  spring,  in  soil  on  grass- 
land. The  larvae  usually  live  two  years  in  the  soil,  then 
pupate  in  July  and  August,  and  are  finally  transformed 
into  beetles  in  about  four  weeks.  The  larvae  both  eat 
and  bore  the  stems  and  roots  of  plants.  No  success- 
ful remedy  has  been  proposed.  When  damage  is  expected, 
the  corn  may  be  planted  more  thickly,  depending  on  thin- 
ning where  the  wireworms  do  not  reduce  the  stand.     When 


ANIMAL   AND  INSECT  ENEMIES  217 

replanting  a  field  injured  by  wireworms  the  new  rows  are 
planted  midway  between  the  old,  leaving  the  old  plants 
as  food  for  the  worms. 

Note.  The  above  pests,  cutworms,  grubs,  and  wireworms,  give  most 
trouble  on  grass  sod.  They  seldom  give  trouble  after  cultivated  crops 
where  clean  culture  has  been  practiced. 

There  are  two  insects  that  are  most  troublesome  where 
continuous  corn  culture  is  practiced  —  the  corn  rootworm 
and  the  root-louse. 

Corn  rootworm 

There  are  two  species,  known  as  the  Western  and  the 
Southern  corn  rootworm.  The  larvae  are  similar  and 
work  in  the  same  way,  though  the  beetles  differ  in  color. 
In  early  fall  the  female  beetles  lay  about  a  dozen  eggs  in 
the  ground  near  the  corn  roots.  These  remain  over  winter 
and  hatch  the  next  spring.  The  larvae  are  about  the 
size  of  a  pin  and  two-fifths  inch  in  length,  almost  colorless 
except  for  the  head,  which  is  yellow.  They  do  most  harm 
in  July  and  August.  Starting  near  the  tip  of  a  large  root 
they  bore  inside  the  root,  toward  the  plant.  As  they 
multiply  rather  slowly  and  as  corn  is  their  only  host 
plant,  the  rootworms  are  serious  only  where  the  land  has 
been  in  continuous  corn  culture  for  three  or  more  years 
in  succession. 

Corn  root-louse 

Injury  from  the  corn  root-louse  is  very  irregular,  due 
no  doubt  to  its  natural  enemies  which  ordinarily  keep 
it  in  check.  When  unrestrained,  however,  it  increases  so 
rapidly  that  it  may  become  very  injurious  in  a  short  time. 
Usually  its  injury  occurs  in  spots  rather  than  over  the 
whole  field,  due  probably  to  local  centers  of  infection 
from  which  it  spreads  rapidly.     During  the  summer  the 


218  CORN   CROPS 

wingless  females  produce  living  young  continuously,  which 
in  turn  at  the  end  of  a  few  daj^s  also  begin  producing  young. 
The  lice  live  on  the  juices  that  they  suck  from  the  corn 
roots.  Winged  females  occur  occasionally,  which  estab- 
lish new  colonies.  In  the  fall  ])oth  winged  males  and 
females  appear.  This  last  brood  lays  eggs  which  live 
over  winter.  Ants  are  often  associated  with  plant  lice 
and  it  is  thought  that  they  assist  in  protecting  them  and 
in  caring  for  the  eggs. 

No  practical  way  of  restraining  the  lice  has  been  sug- 
gested, except  that  early  plowing  and  clean,  thorough 
preparation  of  the  land  will  destroy  to  a  large  degree 
those  present  in  the  soil. 

The  corn  ear  worm 

The  ear  worm  is  the  larva  of  a  moth.  Two  to  seven 
broods  are  produced  each  year,  depending  on  latitude, 
about  four  broods  being  the  average  at  the  40th  parallel. 
It  is  the  brood  produced  at  silking  time  that  is  most 
injurious.  The  worms  eat  off  the  grains  near  the  tip  of 
the  ear,  not  only  destroying  directly  considerable  grain, 
but  also  opening  a  way  for  fungous  diseases  and  ear  rot. 

Migratory  insects 

Chinch  hugs.  —  While  chinch  bugs  breed  in  cornfields, 
the  principal  damage  is  due  to  migrating  bugs  from  adja- 
cent grainfields  after  harvest.  The  migration  o^  wing- 
less bugs  is  prevented  by  barriers,  such  as  a  dust  mulch 
10  feet  wide,  harrowed  every  day  to  keep  loose,  or  a  plow 
furrow  with  post  holes  every  2  rods  where  the  bugs  collect 
and  may  be  destroyed  by  kerosene.  A  barrier  of  tar  is 
sometimes  used. 


ANIMAL   AND  INSECT  ENEMIES 


219 


Fig.  73.  —  Ear  of  corn  showing  corn  smut. 


220  COBN  CROPS 

Army  worms.  —  Where  army  worms  migrate,  the 
remedy  generally  recommended  is  to  establish  a  post- 
hole  barrier  by  plowing  several  furrows  toward  the  colony ; 
in  the  bottom  of  the  last  furrow,  dig  post  holes  into  which 
the  army  worms  fall  and  are  killed  with  kerosene. 

DISEASES   OF   CORN 

150.  The  diseases  affecting  corn  are  the  common  corn 
smut  (  Ustilago  zea)  and  certain  ear  rots,  the  most  serious 
of  which  is  caused  by  a  fungus  known  botanically  as 
Diplodia  zea.  Other  forms  of  ear  rot  are  caused  by  species 
of  Fusarium.  Both  these  diseases  live  over  on  infected 
stalks  and  ears,  producing  spores  abundantly  the  follow- 
ing spring  and  summer  to  infect  the  new  crop.  The  only 
remedy  is  to  gather  up  and  destroy  by  fire  the  infected 
material. 

Corn  is  remarkably  free  from  injurious  diseases.  It  is 
rarely  that  the  loss  from  smut  or  ear  rot  in  a  field  will 
amount  to  so  much  as  1  per  cent.  Occasionally  serious 
loss  occurs. 

References  on  insects  injurious  to  corn :  — 
111.  Agr.  Exp.  Sta.,  Bui.  44.     Insect  Injuries  to  the  Seed  and 

Root  of  Indian  Corn.     1896. 
111.  Agr.  Exp.  Sta.,  Bui.   79.     The  Corn  Bill-bugs  in  Illinois. 

1902. 
111.   Agr.   Exp.   Sta.,   Bui.   95.      The    More    Important    Insect 

Injuries  to  Indian  Corn.     1904. 
111.   Agr.    Exp.    Sta.,    Bui.    104.     Field   Experiments    and   Ob- 
servation on  Insects  Injurious  to  Indian  Corn.     1905. 
111.  Agr.    Exp.    Sta.,    Bui.   130.      Experiments   with  Repellents 

against  the  Corn  Root-aphis.     1905  and  1906. 
111.  Agr.   Exp.   Sta.,     Bui.   131.      Habits  and  Behavior  of  the 

Cornfield  Ant.     1908. 
U.  S.  Dept.  Agr.,  Farmers'  Bui.  259.      Corn  Bill-bugs  and  Root 

Louse. 


ANIMAL   AND  INSECT  ENEMIES  221 

N.  C.  Agr.   Exp.  Sta.,    Bui.    203.     Corn    Weevils    and  Other 

Grain  Insects. 
Ky.  Agr.  Exp.  Sta.,  Bui.  145.     Corn  Pests. 
Ala.  Agr.  Exp.  Sta.,  Circ.  8.     Budworms  in  Corn. 
U.  S.  Dept.  Agr.,  Bur.  Ent.  Bui.  85.     The  Corn  Root  Aphis  and 

Seed  Corn  Ground  Weevil. 

References  of  corn  diseases :  — 

Kans.  Agr.  Exp.  Sta.,  Bui.  23.     Corn  Smut. 

Nebr.  Agr.  Exp.  Sta.,  Bui.    11.     Smut  of  Indian  Corn. 

U.  S.  Dept.  Agr.,  Farmers'  Bui.  69.     Corn  Smut. 

U.  S.  Dept.  Agr.,  Farmers'  Bui.  234.     Dry  Rot  of  Corn. 

III.  Agr.  Exp.  Sta.,  Bui.  133.     Ear  rots  of  Corn. 


CHAPTER  XIX   . 
HARVESTING   THE  CORN  CROP 

151.  In  the  New  England  States,  where  corn  culture 
first  developed,  it  was  the  custom  from  the  beginning  to 
harvest  the  stalk  as  well  as  the  ears.  "  Topping  "  was 
a  common  practice,  the  stalk  above  the  ear  being  cut  off 
for  forage  when  immature,  and  later,  when  the  ears  had 
matured,  these  being  "  snapped  "  off  and  stored  in  barns 
to  be  "  husked." 

With  the  opening  up  of  the  North  Central  and  Western 
States,  from  1840  to  the  present  time,  corn  became  an 
important  article  of  commerce.  The  acreage  of  corn 
increased  rapidly  and,  with  little  use  for  the  stover,  the 
custom  of  harvesting  only  the  ears  became  general. 

In  the  Southern  States,  the  corn  area  has  never  been 
extensive  and  a  part  of  the  forage  has  generally  been  saved. 
The  custom  of  "  topping  "  and  "  stripping  "  has  been 
more  general  in  the  Gulf  States  than  in  other  regions. 

Corn  has  also  been  found  to  be  the  cheapest  and  best 
crop  for  silage ;  in  dairy  regions  throughout  the  North- 
eastern States,  corn  is  grown  principally  for  silage,  the 
entire  crop  of  large  dairy  regions  being  utilized  in  this 
way. 

In  the  Central  and  Western  States,  only  a  small  propor- 
tion of  the  stalks  are  harvested  for  either  silage  or  stover, 
but  the  practice  of  harvesting  the  entire  plant  is  increas- 
ing.    It  is  customary,  when  only  the  ears  are  harvested, 

222 


HABVESTING   THE  CORN  CROP 


223 


^^^Km^f!S»^ -:y-:  ■ 

^ 

Wr  ■ 

J 

224 


CORN    CROPS 


to  turn  the  farm  live  stock  into  the  fields  during  the 
winter  months  to  eat  what  they  will  of  the  leaves,  husks, 
and  smaller  parts  of  the  stalk. 

TIME    OF   HARVESTING 

152.  The  object  should  be  to  harvest  at  such  a  time  as 
to  secure  the  maximum  amount  of  digestible  food.  The 
total  dry  weight  continues  to  increase  up  to  the  time  of 
ripening,  as  shown  by  the  following  data :  — 

TABLE  LIII 

Increase  of  Dry  Weight  as  reported  by  Three   Stations 


Approximate 
Date 

Yield  of  Dry  Matter  per  Acre 

Condition  when 
h-\kvested 

Nev; 

Yorki 

(Geneva) 

Pounds 

Michi- 
gan 2 
Pounds 

Kansas^ 
Pounds 

Aver- 
age 
Pounds 

Percent- 
age of 
Increase 

Ears  in  silk  . 
Ears  in  milk 
Ears  in  glaz- 
ing .     .     . 
Ears  ripe 

Aug.  10-15 
Aug.  25 

Sept.  15 
Sept.  25 

3,000 
4,300 

7,200 
8,000 

3,670 
5,320 

7,110 
8,020 

6,868 

7,716 
9,548 

3,335 
5,496 

7,342 
8,523 

65 

33 

16 

1  Ann.  Rpt.  1889. 

3  Kans.  Agr.  Exp.  Sta. 


2  U.  S.  Dept.  Agr. 
Bui.  30  :  181-207. 


Farmers'  Bui.  97:  12. 


At  the  time  when  corn  is  in  tassel  or  in  silk,  less  than 
one-half  the  dry  weight  has  been  developed.  Increase 
in  dry  weight  continues  up  to  maturity.  There  was  an 
average  increase  of  16  per  cent  from  the  time  corn  was 
glazed  to  time  of  maturity.  There  is  an  increase  not 
only  in  total  dry  weight,  but  in  all  valuable  constituents, 
as  shown  by  the  following  data  from  the  Michigan  sta- 
tion :  — 


HARVESTING   TUB  CORN   CROP 


225 


TABLE   LIV 

Yield  per  Acre  of  Green  Fodder,  Dry  Matter,  and 
Nutrients 


Time  of  Cutting 


August  10  (tasseled) 
August  25  (in  milk) 
September    6    (glaz- 
ing)      

September  15  (ripe) 


Green 
Fodder 

Dry 
Mat- 
ter 

Pro- 
tein 

Nitro- 
gen- 
free 
Extract 

Fat 

21,203 
25,493 

25,865 
23,007 

3,670 
5,320 

7,110 
8,020 

472.7 
576.0 

711.0 
696.9 

1,828 
3,212 

4,554 
5,356 

67.9 
143.1 

199.0 
242.6 

Fib  I 


1,010 
1,148 

1,294 
1,413 


Not  only  does  the  total  yield  increase,  but  the  quality 
improves  with  maturit}^  The  large  group  of  compounds 
under  the  head  ''  nitrogen-free  extract  "  are  not  all 
equally  valuable  for  feeding  purposes.  Starch  and  the 
sugars  are  the  most  valuable  and  both  increase  in  propor- 
tion as  the  plant  matures,  due  to  the  development  of  ear, 
as  shown  by  Jordan  of  the  Maine  station.^*  ^ 


TABLE    LV 


August  15,  ears  beginning  to 

form 

August   28,    a  few    roasting 

ears 

September    4,    all     roasting 

ears 

September    12,    some     ears 

glazing        

September  21,  all  ears  glazed 


Percentage  of 
Starch  and  Sugar 
IN  Nitrogen- 
free  Extract 


Pounds  of  Starch 

AND  Sugar 
produced  per  Acre 


358.5 

1,172 

1,545 

1,764 
2,244 


1  Maine  Agr.  Exp.  Sta.,  Bui.  17:4:. 

2  U.  S.  Dept.  Agr.,  Farmers'  Bui.  97  :  12. 


226 


CORN   CROPS 


RELATIVE  PROPORTION  OF  PARTS 

153.    Before    considering    the    time    and    method    of 

harvesting  the  whole  plant,  it  will  be  well  to  note  the 

relative  proportion  and  value  of  the  different  parts  of  the 

corn  plant  at  various  stages  of  growth.     The  Michigan 

station  has  studied  this  subject  and  reported  the  following 

results :  ^  — 

TABLE   LVI 

Percentage  of  Total  Dry  Matter  in  Leaves,  Stalks,  and 
Ears  of  Corn  Plants  at  Four  Stages  of  Growth  (Mich- 
igan Station,  1896) 


Time  of  Cutting 

Percentage  of  Total  Dry  Matter 

Leaves 

stalks 

Ears 

August  24  (in  milk)  .... 

August  31 

September  7  (glazing)    .     .     . 
September  14  (ripe)       .     .     . 

36.41 
33.63 
30.03 
21.77 

34.27 
25.52 
25.53 
31.91 

29.32 
40.85 
44.44 
46.32 

.       COMPOSITION    OF   PARTS 

154.  The  total  dry  weight  alone  does  not  give  a  com- 
parative statement  of  the  relative  feeding  value  of  the 
parts  of  a  corn  plant.  The  leaves  are  very  high  in  al- 
buminoids, while  the  stalks  are  low  in  these  compounds. 
Pound  for  pound,  leaves  are  about  twice  as  valuable  as 
stalks.  A  further  study  of  the  distribution  of  the  princi- 
pal compounds  of  the  plant  at  different  stages  of  growth 
is  reported  as  follows  :  — 

1  U.  S.  Dept.  Agr.,  Farmers'  Bui.  97:  9-12. 


HARVESTING   THE  CORN   CROP 


227 


TABLE   LVII 

Distribution  of  Albuminoids  and  Nitrogen-free  Extract 
IN  Leaves,  Stalks,  and  Ears  of  Corn  at  Different 
Stages  of  Growth 


Albuminoids 

Nitrogen-free  Extract 

Leaves 

Stalks 

Ears 

Leaves 

Stalks 

Ears 

August  24  (in  milk) 

August  31 

September  7  (glazing)  . 
September  14  (ripe) 

52.50 
51.06 
42.71 
30.60 

10.00 
2.53 
5.19 

10.70 

37.50 
46.41 
52.10 
58.70 

38.50 
28.40 
20.50 
15.90 

17.50 
23.64 
25.30 
29.40 

44.00 
47.96 
54.20 
54.70 

The  above  tables  show  very  clearly  the  shift  in  relative 
proportion  of  dry  weight  and  important  food  constituents 
from  leaves  and  stalk  to  ear,  as  growth  progresses.  From 
the  data  presented  in  the  last  five  tables  it  would  seem  that 
corn  should  be  allowed  to  stand  until  quite  mature  before 
harvesting,  since  the  total  yield  and  quality  apparently 
improve.  There  are  two  considerations  against  this : 
the  loss  of  leaves,  and  the  fact  that  both  leaves  and  stalk 
become  less  palatable  with  maturity. 


RELATIVE    VALUE    OF   PARTS 

155.  From  the  last  two  tables  it  appears  that  at  the 
time  the  ear  is  in  the  ''  milk  "  stage,  the  relative  dry 
matter  is  about  equally  distributed  between  leaves,  stalks, 
and  ears,  although  40  to  50  per  cent  of  the  total  nutrients 
are  in  the  leaves  alone.  There  is  then  a  gain  in  ear  until 
46  per  cent  of  the  dry  weight  and  about  56  per  cent  of  the 
nutrients  are  found  in  the  ear. 


228 


CORN  CROPS 


RELATIVE    FOOD    VALUE    OF    EARS   AND    STOVER 

At  the  time  corn  would  be  cut  for  silage  or  fodder, 
when  the  ears  are  glazed,  about  40  per  cent  of  the  protein 
and  20  per  cent  of  the  nitrogen-free  extract  are  in  the  leaves  ; 
or,  of  the  total  food  value  of  the  plant  at  this  time,  approxi- 
mately 30  per  cent  is  in  the  leaves,  15  per  cent  in  the  stalk, 
and  55  per  cent  in  the  ear. 

Armsby  ^  compiled  the  data  from  four  stations  and  cal- 
culated the  yield  of  ears  and  stover  to  be  as  follows :  — 

TABLE   LVIII 


Station 


New  Jersey  (dent)  . 
Connecticut  (flint)  . 
Wisconsin  (dent) 
Pennsylvania  (dent) 
Average  .      .     . 


Ears 


4,774 
4,216 
4,941 
3,727 
4,415 


Stover 


4,041 
4,360 
4,490 
2,460 
3,838 


The  above  average  shows  that  about  53  per  cent  of  the 
crop  by  weight  is  ears;  but  the  ears  contain  a  higher 
percentage  of  digestible  nutrients  than  does  the  stover, 
and  a  calculation  of  the  digestible  nutrients  in  the  above 
shows  about  63  per  cent  in  the  ear  and  37  per  cent  in  the 
stover.  The  above  figures  represent  the  distribution  of 
nutrients  at  the  time  the  stover  is  cut  for  forage,  but  do 
not  indicate  the  final  distribution  of  digestible  nutrients. 
Fodder  is  usually  cut  when  the  ears  are  glazed  in  order  to 
save  the  valuable  leaves,  and  about  ten  days  before  it  is 
ripe.  But  during  this  period  there  is  considerable  trans- 
location of  sugars  and  starch  from  the  leaves  and  stem  to 


1  Penn.  Agr.  Exp.  Sta.,  Rpt.    1887. 


HABVESTING    THE   CORN   CROP  229 

the  ear,  so  that  in  the  fully  matured  corn  crop,  under 
normal  conditions,  between  60  and  70  per  cent  of  the 
digestible  nutrients  will  be  in  the  ears. 

This  ratio  would  not  apply  to  corn  planted  thick  for 
silage,  when  the  proportion  of  stover  is  increased  without 
decreasing  the  yield  of  ears. 

There  is  also  considerable  increase  in  total  weight 
between  the  time  the  ears  are  glazed  and  the  time  when 
they  are  ripe,  usually  amounting  to  about  10  per  cent. 
The  value  of  stover  obtained  must  be  decreased  by  what- 
ever loss  is  occasioned  by  early  harvesting.  Charging 
this  loss  against  the  stover,  it  would  appear  that  the  total 
feeding  value  of  the  crop  is  increased  about  25  per  cent  by 
harvesting  the  stover  when  the  ears  are  glazed,  in  com- 
parison with  allowing  the  crop  to  mature  and  harvesting 
only  the  ears. 

In  conclusion,  corn  should  be  permitted  to  become  as 
nearly  mature  before  harvesting  as  is  practicable.  As 
pointed  out  heretofore  (page  227),  two-thirds  of  the  value 
of  the  stover  is  in  the  leaves,  and  it  is  therefore  important 
to  save  these.  In  a  humid  climate,  with  fall  rains,  it  is 
often  possible  to  allow  corn  to  stand  until  most  of  the 
ears  are  mature  before  cutting ;  but  in  a  region  with  dry 
falls  and  windy  weather  the  harvesting  must  be  done 
seven  to  ten  days  earlier,  if  the  leaves  are  to  be  saved. 

TIME  OF   HARVESTING    FOR   SILAGE 

156.  When  the  silo  first  came  into  use,  the  custom  was 
to  use  ver}^  immature  material.  It  was  found  in  time 
that  silage  from  mature  corn  was  better  in  quahty  and  the 
yield  was  greater.  There  is  a  limit,  however,  in  this 
direction.     Silage,  in  order  to  keep  well,  must  pack  closely, 


230 


CORN   CROPS 


and   as  nearly   as   possible,   all   air   must    be   excluded. 

Corn  too  mature  cannot  be  packed  closely  enough, 
though  sprinkling  with  water  and 
careful  tramping  will  allow  the 
ensilaging  of  corn  even  when  more 
than  half  the  ears  might  be  con- 
sidered ripe.  As  a  general  rule, 
when  the  husks  have  mostly 
turned  yellow,  and  two  to  four 
bottom  leaves  have  turned,  is  the 
proper  time. 

Good  silage  contains  about  75 
per  cent  water,  and  it  is  doubtful 

whether  it  would  be  practicable  to  ensile  corn  containing 

less  than  65  per  cent  moisture. 


Fig.  75. — A  modern  silage 
cutter,  with  blower  at- 
tachment, for  deUvering 
the  cut  silage. 


METHODS    OF   HARVESTING 

157.  The  four  methods  of  harvesting  maize  are  as  fol- 
lows :  — 

1.  Stripping:    leaves  removed  while  green  for  forage, 
and  ears  husked  later. 

2.  Topping :  tops  cut  off  above  ear  for  forage,  and  ears 
husked  later. 

3.  Ears  only  harvested,  stalks  left  in  field. 

4.  Entire  plant  harvested  for  silage  or  fodder. 


Harvesting  by  hand 

158.  Stripping  and  topping  are  practiced  in  the  belief 
that  in  this  way  the  forage  may  be  obtained  while 
green  and  in  the  right  condition  to  harvest,  while  the 
ears  are  allowed  to   remain   and   mature.     It   has   been 


HARVESTING   THE  CORN  CROP 


231 


232  CORN  CROPS 

shown/  however,  that  both  stripping  and  topping  reduce 
the  yield  of  grain,  so  that  it  is  doubtful  whether  the  total 
yield  of  grain  secured  is  greater  than  when  the  whole 
plant  is  harvested  as  fodder.  The  loss  of  shelled  corn  has 
generally  amounted  to  10  to  20  per  cent,  which  is  about 
the  usual  loss  when  harvested  as  fodder. 

The  Texas  station  reports  the  labor  expense  of  topping 
and  stripping  to  be  as  follows :  — 

Tops  only:  Cost  per  ton  of  dry-cured  fodder  .  .  .  .  $2.13 
Leaves  only:  Cost  per  ton  of  dry-cured  fodder  ....      7.67 

As  it  takes  about  four  acres  to  produce  a  ton  of  leaves 
and  half  as  much  for  a  ton  of  tops,  the  value  of  the  forage 
secured  does  not  compensate  for  the  loss  of  grain  and 
cost  of  harvesting. 

159.  Hand  cutters.  —  Probably  the  first  tool  used  in 
harvesting  fodder  was  the  hoe.  Corn  knives  came  into 
use  in  time,  those  made  from  old  scythe  blades  being  the 
most  common  at  first.  Corn  "  hooks  "  were  also  made 
by  inserting  a  short  blade  at  about  right  angles  in  a  short 
wooden  handle.  There  are  several  standard  types  of 
knives  and  hooks  on  the  market. 

Horse-drawn  cutters 

160.  The  first  horse-drawn  cutters  to  have  a  general 
use  were  sleds,  drawn  astride  of  the  corn  row,  with  a 
heavy  knife  attached  in  front  at  the  right  height  to  cut 
off  the  corn  plants,  or  drawn  between  two  corn  rows  with 
a  heavy  knife  attached  to  one  or  both  sides  for  cutting 

1  Miss.  Agr.  Exp.  Sta.,  Bui.  33:  63.     1895. 
Penn.  Agr.  Sta.,  Rpt.  1891 :  58-60. 
Ga.  Agr.  Exp.  Sta.,  23:  81-82.     1893. 
Ark.  Agr.  Exp.  Sta.,  Bui.  £4:  120. 


IT— r 


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JJ 

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J3 

28 

27 

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67 

<J7  JS   cJ9 

JO 

29    26 

69    66 

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J/    J2   2  J 

60 

66 

4 

J"      8 

2  J    22 

64 

40 

6       7 

24   2/ 

20 

4/ 

46 

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42    4d- 

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cfj   J2    J/ 

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48 

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60 

Fig.  77.  —  A  corn  hook  and  knives  used  in  harvesting  corn  fodder.  A 
"horse"  used  in  shocking  corn  fodder.  A  home-made  sled  cutter. 
The  sled  is  drawn  by  a  horse  between  two  rows,  the  stalks  being  cut 
by  sharp  knives  on  each  side.     Two  operators  stand  on  the  sled. 

The  lower  figure  illustrates  a  system  of  cutting  by  hand,  in  order  to 
economize  steps. 

233 


2M  CORN  CROPS 

the  plants.  Later,  wheels  were  substituted  for  runners 
and  seats  were  provided  for  the  men.  Some  cutters  have 
large  platforms  to  carry  the  green  fodder  until  enough  has 
been  accumulated  for  a  shock.     There  is  no  labor  saved 


Fig.  78.  —  A  two-row  corn  cutter  mounted  on  wheels.    The  two  operators 
stand  between  the  wheels. 


by  having  a  large  platform,  and  the  most  popular  type 
is  that  in  which  there  is  room  for  only  a  large  armful  to 
be  collected  at  a  time. 

The  corn  hinder 

161.  The  first  successful  corn  binders  were  introduced 
about  1895  and  have  steadily  increased  in  popularity. 
The  corn  is  bound  in  bundles  of  convenient  size,  and  with 
a  bundle  carrier  six  to  eight  bundles  may  be  collected 
before  dropping  windrows  to  be  shocked  up  later  or  drawn 
to  the  silo. 


HARVESTING   THE  CORN  CROP 


235 


Shocking  corn 

162.   The  ordinary  custom  in  curing  fodder  is  to  leave  it 
in  shocks  for  one  to  three  months.     It  is  then  sufficiently 


Fig.  79.  —  Corn  fodder  harvester  in  section. 

cured  to  husk  or  store  in  barns  or  stack  yard.  It  is 
often  left  in  the  field  to  be  hauled  as  needed  during 
the  winter. 

Size  of  shocks 

163.  The  exposure  and  loss  is  greater  in  small  shocks 
than  in  large.  Where  fodder  is  green,  the  shocks  must 
be  small  if  the  corn  is  set  directly  into  shock,  ordinarily 
one  hundred  to  one  hundred  fifty  hills  being  enough. 
When  cured  it  is  often  practicable  to  set  two  or  three 
shocks  together  or  to  stack.  When  the  fodder  can  be 
allowed  to  partly  cure  before  shocking,  as  in  harvesting 
with  a  binder,  the  shocks  should  be  made  as  large  as  is 
practicable. 


236 


CORN  CROPS 


HARVESTING   THE  CORN   CROP  237 


Setting  up  shocks 

164.  When  cutting  corn  with  knives,  it  is  customary  to 
tie  four  hills  together  for  a  ''  horse  "  in  the  place  where  it 
is  proposed  to  place  a  shock.  In  other  cases  a  "  horse  " 
is  made  as  illustrated  in  Fig.  77.  In  setting  up  bundles 
after  a  corn  binder,  a  "  horse  "  is  not  necessary. 


Tying  shocks 

165.  After  the  shock  is  well  set  up,  the  tops  of  the  out- 
side stalks  should  be  tucked  under  and  the  shock  securely 
tied  with  binder  twine.  A  rope  with  iron  hook  on  one 
end,  or  a  quirt,  is  useful  in  drawing  the  shock  before  tying. 

When  corn  is  cut  by  hand,  some  steps  will  be  saved  by 
following  a  systematic  plan,  in  cutting  the  hills  for  each 
armful.  Such  a  plan  for  a  shock  ten  hills  square  is  illus- 
trated in  Fig.  77. 

Husking  fodder  corn 

166.  The  fodder  may  be  husked  in  the  field,  a  common 
practice  in  the  West,  or  as  common  in  the  East,  hauled 
to  the  barn  to  be  husked  later,  or  hauled  to  a  shredder. 
The  shredder  deUvers  the  shredded  fodder  and  husked 
ears  in  separate  piles.  When  husking  by  hand  in  the 
field  the  ears  are  often  thrown  into  piles,  to  be  collected 
later  with  a  wagon.  A  more  convenient  way  is  to  husk 
directly  into  the  wagon.  A  high  "  throwboard  "  should 
be  put  on  the  wagon  box  opposite  the  husker.  A  light 
frame  on  wheels  may  be  attached  to  the  rear  of  the  wagon 
across  which  the  fodder  corn  is  thrown  for  husking.  This 
allows  the  husker  to  stand  while  at  work. 


238 


CORN   CROPS 


Shredding  fodder 

167.  Zintheo  makes  the  following  statement :  ^  "  Be- 
tween 1880  and  1890,  a  great  deal  of  attention  was  given 
to  threshing  corn.  This  practice  so  battered  the  stalk  as 
to  make  every  part  of  it  available  as  a  cattle  food.  Fodder 
cutters  had  been  in  use  for  many  years  yet  this  method  of 
preparing  corn  fodder  left  the  fibrous  part  of  the  stalk  in 
a  tough  woody  condition  which  cattle  did  not  relish.  The 
bruising  and  shredding  action  of  the  thresher  put  the 
stalk  in  a  more  palatable  form.  The  repeated  shortages 
and  failures  of  the  hay  crop  during  the  decade  1880-1890, 


^A/f(/M4r/c  S7>fc/fr^ 


Fig.  81.  —  Combined  shredder  and  busker. 

together  with  the  results  of  attempts  at  threshing  corn, 
led  to  the  invention  of  the  combined  husker  and  shredder, 
which  takes  the  stalks  with  the  ears  on  them  and  prepares 
the  stalks  for  feeding." 

Shredding  fodder  is  generally  considered  as  an  economic 
way  of  preparing  corn  fodder  for  feed.  In  humid  climates 
there  is  sometimes  trouble  with  the  shredded  fodder  heat- 
ing when  piled  in  large  quantities,  unless  care  is  taken  to 
shred  only  fodder  in  a  fairly  dry  condition. 

1  U.  S.  Dept.  Agr.,  Office  Exp.  Sta.,  Bui.  ^75;  40. 


HARVESTING   THE  CORN  CROP 


239 


Hauling  fodder  corn 

168.  When  there  is  snow,  a  sled  with  fodder  rack  is 
most  convenient.  At  other  times  and  for  drawing  silage, 
a  low  down  rack  on  wheels  is  desirable. 


Fig.  82. 


Husking  peg  and  husking  hook.     The  peg  is  best  for  fodder 
corn  and  the  hook  for  standing  corn. 


Harvesting  ears  by  hand 

169.  In  the  Corn  Belt  States,  only  the  ears  are  harvested 
on  perhaps  nine-tenths  of  the  area.  The  method  is  to 
husk  directly  into  a  wagon.  A  ''  throw-board  "  about 
30  inches  high  is  put  on  the  wagon-box  on  the  far  side 
from  the  husker.  The  husker  takes  two  rows  at  a  time  and 
usually  one  man  to  a  wagon.  An  average  day's  husking 
in  good  corn  is  60  to  75  bushels  of  shelled  corn.  The 
husker  uses  a  peg  or  hook  in  the  palm  of  his  hand  to  assist 
in  tearing  off  the  husks. 


240 


CORN  CROPS 


Harvesting  ears  by  machinery 

170.  For  at  least  fifty  years,  attempts  have  been  made 
to  devise  mechanical  corn  pickers  to  operate  in  the  field. 
Within  the  past  few  years,  machines  have  been  perfected 


Fig.  83.  —  Method  of  husking  corn  from  the  field  in  corn  belt. 


HARVESTING    THE  CORN  CROP  241 

that  do  the  work  in  a  satisfactory  manner,  provided  the 
stalks  stand  up  well  and  too  many  ears  have  not  fallen 
to  ground.  At  best,  some  ears  are  left  in  the  field, 
which  must  be  picked  up  by  hand.  In  some  cases,  live 
stock  are  turned  in  to  gather  up  ears  that  are  left.  As 
the  machine  requires  six  horses  to  draw  it  and  two  more 
teams  to  draw  the  ears  away,  it  is  only  practical  in  large 
fields.     A  machine  will  husk  about  eight  acres  a  day. 

Comparative  cost  of  harvesting  methods 

171.  Zintheo  ^  has  collected  and  summarized  data  on 
comparative  cost  of  different  methods  of  harvesting  corn. 
He  gives  the  following  estimate  as  comparative  cost  in  the 
corn-belt,  where  the  corn  is  producing  an  average  of  44 
bushels  per  acre  :  — 

TABLE   LIX 

Cost  of  Harvesting  Corn  by  Various  Methods 

Average  data  for  harvesting  by  hand 

Cost  of  implement $1.00 

Acres  one  man  harvests  per  day 1.47 

Cost  of  cutting  and  shocking $1.50  per  acre 

Average  data  for  harvesting  with  sled  harvester 

Cost  of  implement $5  to  $50 

Acres  2  men  and  1  horse  harvest  per  day  .     .  4.67 

Cost  of  cutting  and  shocking $1.18  per  acre 

Average  data  for  harvesting  with  corn  binder 

Cost  of  implement $125.00 

Acres  cut  per  day  by  1  man  and  3  horses  .     .  7.73 

Acres  shocked  per  day,  1  man 3.31 

Cost  of  cutting  and  shocking $1.50  per  acre 

1  Zintheo.  Corn  Harvesting  Machinery.  U.  S.  Dept.  Agr.,  Office  of 
Exp.  Sta.,  Bui.  173:  46. 


242 


CORN   CROPS 


Cost  per  bushel  of  picking  and  husking  corn 

CENTS 

By  hand  from  field 3.5 

Team  for  cribbing 1. 

By  hand  from  shock        5.3 

Team  for  cribbing 79 

By  corn  picker  from  field 4.1 

By  buskers  and  shredder  from  shock     .     .     4.5 

The  relative  cost  of  methods  will  differ,  depending  prin- 
cipally upon  the  price  of  labor. 

Storing  ears 

172.  The  ears  are  usually  stored  in  slatted  cribs  to 
provide  ventilation.     If  a  good  roof  is  provided,  there  is 


^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^j^^^^^r^/" 

•^   ^'■^f#^"1iii[i1ifl}lipWfi'"i"''      1    '     '    1 

^^^^ 

^m, '  '0^     '    *^'°  -~  " 

Fig.  84. 


A  good  type  of  farm  corn  crib,  and  farm  elevator  used  in 
unloading. 


seldom  loss  from  rotting  in  the  crib.  Rats  and  mice 
cause  considerable  loss  where  corn  is  stored  for  several 
months  or  more  and  it  is  important  to  have  cribs  rodent 


HARVESTING    THE  CORN  CROP 


243 


proof.  Ventilated  sheet-iron  cribs  are  now  on  the 
market,  that  are  rodent-proof  if  set  on  a  cement  foun- 
dation. Wooden  cribs  can  be  made  rodent-proof  by  lin- 
ing with  hardware  netting  or  if  constructed  on  a  cement 
foundation.  Where  a  cement  floor  and  foundation  are 
used,  care  must  be  taken  to  provide  ventilation  under- 
neath by  means  of  a  raised  board  floor.  The  floor  may 
be  slated  and  made  in  movable  sections  to  facilitate  clean- 
ing beneath. 

Shrinkage  in  curing  fodder  and  silage 

173.  If  the  total  dry  matter  and  protein  content  of 
corn  fodder  be  ascertained  at  the  time  of  storage  either  as 
fodder  or  silage,  it  may  be  determined  that  there  is  a  con- 
stant loss  in  both  for  at  least  a  year.  The  amount  of  this 
loss  as  determined  by  the  Wisconsin  station  is  summarized 
as  follows :  — 

TABLE  LX 

Loss    IN    Curing    Corn    in  Silo  or  as    Fodder    (Wisconsin 
Station,  Three-year  Average) 


Method 

Green 
Fodder 
Pounds 

Silage  or 

Dry 

Fodder 

Pounds 

Loss  IN 
Pounds 

Curing 
Per  Cent 

(a)  Ensilage  method 

Dry  matter       .     .     . 

Crude  protein  .     .     . 
(6)  Field  cured 

Dry  Matter      .     .     . 

Crude  protein  .     .     . 

35,602 
2,910 

39,448 
3,102 

28,300 
2,312 

31,428 
2,619 

7,281 
597 

8,020 

482 

20.5 
20.6 

20  3 
15.6 

The  Connecticut  station  ^  reports  results  of  an  experi- 
ment in  which  no  loss  was  apparent  while  curing.     Most 

1  Conn.  Sta.,  Rpt.  1889  :  219. 


244  COBN  CROPS 

experiments,  however,  show  field  losses  ranging  from  10  to 
20  per  cent.  A  part  of  this  loss  in  field  curing  is  due  to 
direct  loss  of  leaves  and  portions  of  the  stalk.  Where  direct 
loss  of  material  is  entirely  prevented,  there  is  still  a  loss, 
apparently  due  to  a  slow  process  of  oxidation  or  fermen- 
tation. This  loss  will  go  on  even  when  placed  in  stack  or 
under  cover. 

As  15  to  20  per  cent  of  the  feeding  value  of  corn  fodder 
is  in  the  leaves,  a  large  share  of  the  loss  of  field  curing  is 
due  to  loss  of  leaves,  but  a  part  to  fermentations ;  on  the 
other  hand,  all  loss  in  silos  is  due  to  fermentations. 


Gain  in  gross  weight 

174.  After  fodder  has  become  thoroughly  air  dry,  its 
weight  will  then  vary  with  the  humidity  of  the  air,  as  dry 
fodder  readily  absorbs  moisture.  The  Connecticut  sta- 
tion reports  the  results  with  two  lots  of  fodder  in  1877. 
The  fodder-crop  was  very  heavy,  but  the  fall  being  dry, 
the  two  lots  cured  down  to  27  per  cent  and  36  per  cent 
moisture  respectively,  when  placed  in  the  barn.  The 
winter  was  warm  and  damp,  so  that  5.2  tons  placed  in  the 
barn  Nov.  11,  had  increased  in  weight  to  8.5  tons  by  Feb.  8. 


Shrinkage  of  ear  corn  in  storage 

175.  When  ear  corn  is  stored  as  harvested  in  October 
or  November,  there  is  a  shrinkage  in  total  weight  during 
the  first  year  varying  from  5  to  20  per  cent.  Shrinkage 
is  principally  due  to  drying  out  of  water.  It  is  directly 
related  to  how  well  the  corn  matures,  and  the  dryness  of 
fall  weather.  The  following  data  from  three  experiment 
stations  illustrate  :  — ■ 


HABVESTING    THE  CORN   CROP 


245 


TABLE    LXI 

Shrinkage  of   Corn  in  Crib  as  summarized  from  Results 
OF  Three  Stations 


Month  after  Harvest 


December 
February 
March     . 
April  .     . 
June  . 
August 
September 
October  . 


Kansas  1 

Three-year 

Average 

Per  Cent 


3.26 

5.16 
6.80 
7.44 

8.62 


Illinois  2 

Four  Trials 

Per  Cent 


3.6 

5.7 

14.4 

16.6 


Iowa  5 
One  year 
Per  Cent 


8.7 
10.5 
16.2 
19.4 


»  Kans.  Bui.  U7  :  267.       2  111.  Bui.  113  :  363.      » Iowa  Bui.  43  :  228. 

Results  at  the  Illinois  station  show  practically  no  loss 
the  second  year.  In  fact  after  corn  has  become  thoroughly 
air  dry,  the  weight  will  then  fluctuate  with  the  humidity  of 
the  air,  the  variation  amounting  to  as  much  as  3  per  cent. 
(See  111.  Bui.  113,  p.  363.) 

Shrinkage  is  partly  due  to  the  loss  of  water,  but  as 
pointed  out  by  Ten  Eyck  ^  the  loss  of  moisture  alone  does 
not  account  for  the  entire  decrease  in  weight.  There  is 
a  decrease  in  actual  dry  matter  probably  due  to  some 
process  of  oxidation. 

Marketing 

176.  Corn  is  usually  marketed  as  shelled  corn  and  is 
seldom  shipped  in  ear.  About  60  per  cent  of  the  corn 
crop  is  consumed  on  the  farms  where  produced.  About 
10  per  cent  is  sold  locally  to  feeders  and  about  25  per  cent 

1  Kans.  BmI.  147  :  268. 


246  CORN  CROPS 

finds  its  way  into  the  general  markets.  Of  the  total  crop 
produced  in  the  United  States,  about  3  per  cent  is  ex- 
ported, hence  a  large  share  of  the  corn  reaching  the  general 
market  is  redistributed  in  the  United  States. 

The  ear  corn  is  usually  stored  on  the  farm  in  cribs  hold- 
ing 500  to  5000  bushels.     When  ready  to  market  it  is 


Fig.  85.  —  Large  power  corn  sheller  in  operation  on  a  farm.    Will  shell 
400  bu.  per  hour. 

shelled  out,  with  power  shellers  that  handle  200  to  400 
bushels  per  hour.  The  shelled  grain  is  then  hauled  to  a 
local  elevator  where  it  is  loaded  on  cars  and  shipped  either 
direct  to  a  consumer,  or  to  one  of  the  large  terminal  ele- 
vators, where  the  grain  may  be  stored. 

Drying  corn  for  shipment 
177.  Corn  is  comparatively  easy  to  keep  in  storage,  the 
principal  difficulties  coming  from  excess  moisture.  When 
corn  is  shipped  in  cars,  from  northern  states  to  the  south, 
or  when  loaded  in  ships  for  export,  there  is  great  danger 
that  it  will  "  go  out  of  condition  "  if  containing  higher 
than  15  per  cent  moisture.  Large  commercial  driers  are 
now  in  general  use,  capable  of  drying  several  thousand 
bushels  a  day,  to  12  per  cent  moisture. 


HARVESTING    THE  CORN  CROP 


247 


Cost  of  producing 

178.  The  principal  cost  factors  in  producing  corn  are 
labor,  and  rent  of  land.  The  cost  of  seed  and  fertilizer 
being  minor  factors,  at  present,  in  the  corn-belt,  although 


Fig.  86.  —  Large  cement  grain  tanks,  such  as  are  used  for  storage  at 
terminal  markets.     (Erie  Railway,  Chicago,  111.) 


in  certain  sections  of  the  East  and  South,  the  use  of  fer- 
tilizers on  corn  is  becoming  more  common. 

The  rent  of  land  is  fairly  well  standardized,  being  in 
general  about  $5  per  acre  for  land  capable. of  producing 
40  to  50  bushels  per  acre.  The  amount  of  labor  varies  with 
soil.  The  required  labor  to  produce  an  acre  of  corn  on  the 
heavy  clay  lands  of  the  East  is  probably  twice  that 
required  on  the  prairie  land  of  Iowa  and  would  be  still 


248 


CORN  CROPS 


less  in  central  Nebraska  and  Kansas,  where  listing  is  a 
general  practice. 

The  cost  of  growing  and  harvesting  ears  from  standing 
stalks  has  been  reported  from  many  sources,  the  general 
results  being  illustrated  by  the  following  data :  — 


TABLE  LXII 


Cost  of 

Har- 

vesting 

Ears 

Yield 

Total 
Cost 

Cost 

Date  of  In- 

Cost  per 
Acre  of 

FROM 

Stand- 

PER 

Acre 

PER 

Bush- 

Raising 

ing 
Stalks 

Dol- 

Bush- 

Dol- 

el 

Dollars 

lars 

els 

lars 

Cents 

American    Agri- 

culturist sum- 

marized   from 

several    states 

in    the      corn 

belti.     .     .     . 

1897 

8.43 

1.00 

39.2 

9.43 

24.0 

Minnesota  2   .     . 

1902-04 

{8.25  4 

[3.51 

40  4 

11.76 

29.4 

17.35 

[2.60 

40  4 

9.95 

24.9 

Nebraska  ^     .     . 

1909-10 

10.06 

1.59 

39.3 

11.62 

29.6 

1  Book  of  Corn,  p.  ^  Bureau  of  Statistics,  Bui.  No.  48,  p.  41. 

3  Nebr.  Bui.  122,  p.  9.  ^  Estimated. 

Earlier  estimates  when  both  land  and  labor  were  cheaper 
indicate  that  corn  was  produced  for  20  cents  per  bushel  in 
the  period  from  1885  to  1895.  The  fertility  of  land  is  an 
important  factor  in  the  cost  per  bushel  or  ton,  as  the  ex- 
pense of  raising  is  little  if  any  more  on  good  land  than 
poor. 

'    The  cost  of  harvesting  fodder  corn  and  silage  has  been 
estimated  in  another  place  (page  241). 


CHAPTER  XX 

USES   OF  CORN 

179.  Perhaps  nine-tenths  of  the  corn  crop  is  fed  to  live 
stock.  The  remainder  is  used  in  the  arts,  in  manufac- 
turing glucose,  starch,  corn  meal,  breakfast  foods,  hominy, 
corn  oil,  and  alcohol,  etc.  The  husks  are  used  in  mat- 
ting, the  stalks  and  pith  in  packing,  and  corn  cobs  are 
used  in  making  tobacco  pipes. 

Corn  meal  and  hominy  have  been  important  articles 
of  food  among  American  people  from  Colonial  days. 
The  use  of  corn  as  food  has  declined  since  the  Civil 
War,  probably  due  to  the  large  production  of  wheat  at 
low  cost.  The  principal  corn-meal  market  at  present 
is  in  the  Southern  States,  where  it  is  extensively  used 
by  the  people  of  both  races.  There  is  a  general  but 
light  demand  for  "  fancy  corn-meal "  throughout  the 
country. 

The  two  principal  grades  of  meal  are  whole  meal  and 
"  degerminated  "  meal.  In  the  first  case,  the  whole  corn 
is  ground  and  only  the  coarsest  bran  removed,  giving  a 
yield  of  about  94  pounds  of  meal  from  100  pounds  of  corn. 
This  meal  contains  all  the  germ  which  darkens  the  color 
and  adds  its  own  flavor.  Within  recent  years,  degerminat- 
ing  has  become  general  in  making  fancy  meal.  The  germ 
and  bran  are  all  removed,  the  meal  well  ground  and  bolted, 
giving  about  40  pounds  of  meal  to  100  pounds  of  corn. 
This  meal  is  often  called  "  granulated  "  meal. 

249 


250  COBN    CROPS 

Com  bran  and  germ  meal  are  the  by-products  of  meal 
manufacture,  both  of  which  are  used  for  stock  food,  while 
the  germ  meal  is  also  used  in  the  manufacture  of  prepared 
breakfast  foods. 

Hominy  is  whole  or  cracked  corn  with  the  hull  removed. 
Originally  hominy  was  prepared  by  soaking  the  whole  corn 
in  a  strong  lye  solution,  which  caused  the  hulls  to  loosen 
and  was  then  removed  by  washing,  but  at  present,  the 
hulling  of  commercial  hominy  is  done  with  machinery. 

Grits  is  coarse  ground  hominy,  but  the  commercial 
product  is  usually  prepared  as  an  intermediate  product 
in  the  grinding  of  meal. 

Germ  meal  is  a  by-product  in  the  manufacture  of  corn- 
meal  and  starch  and  is  composed  principally  of  germs. 

Glucose  or  corn  sirup  is  made  by  inverting  the  starch 
of  corn  by  means  of  dilute  hydrochloric  acid.  The 
germ  is  first  removed  and  put  on  the  market  as  germ 
meal  or  pressed  to  extract  the  oil.  Gluten  feed  is  the  resi- 
due after  glucose  is  extracted  and  is  very  rich  in  protein 
compounds  and  has  a  standard  market  value  as  stock 
food. 

Corn  oil  is  extracted  by  pressure  from  the  separated 
germs,  which  are  about  30  per  cent  oil.  The  oil  is  used 
as  a  salad  oil,  in  paints,  or  vulcanized  as  a  substitute  for 
vulcanized  rubber.  The  residue  after  extracting  oil  is 
known  as  corn  oil  cake. 

Starch.  —  Corn  was  an  important  source  of  starch  at  one 
time,  but  potatoes  are  more  commonly  used  at  present. 
The  starch  is  extracted  by  washing  from  the  corn  flour. 
A  residue  is  left  known  as  gluten  feed. 

Distillery  products  are  the  residue  left  as  a  result  of 
distilling  alcoholic  beverages.  The  starch  is  largely 
removed  in  distilling,  leaving  a  iermented  by-product, 


USES   OF  CORN  251 

high  in  protein  content,  which  is  put  upon  the  market  in 
various  forms  as  stock  food. 

Pop-corn  products.  —  A  large  proportion  of  the  pop-corn 
crop  is  utiUzed  with  no  other  preparation  than  popping, 
with  a  small  amount  of  butter  and  salt  added  for  seasoning. 
The  popped  corn  is  also  used  in  various  confections  and  in 
prepared  breakfast  foods. 

Siveet  corn  products.  —  The  sweet  corn  crop  is  utilized 
as  green  corn  on  the  cob,  as  "  canned  "  corn,  and  "  dried  " 
corn.  Dried  corn  was  at  one  time  an  important  home- 
made article  of  food  and  considerable  was  sold  as  a  com- 
mercial product.  Canning  is  the  principal  method  of 
preserving  green  corn  and  has  become  an  important 
commercial  industry. 

Cereal  food  products.  —  Corn,  either  as  grits,  germs,  or 
popped,  is  utilized  to  some  extent  in  various  prepared 
cereal  foods.  A  common  method  is  to  cook  the  cracked 
hominy  until  soft,  then  roll  into  thin  flakes,  which  are 
then  dried.  The  cooking  and  drying  increases  the  soluble 
sugars,  and  more  or  less  carmelizes  the  carbohydrates. 

Corn  meal  is  utilized  in  various  ways.  Corn-meal  mush 
and  samp  is  made  by  simply  boiling  in  water  with  a  little 
salt,  and  is  well  known.  Polenta,  made  in  the  same  way, 
is  said  to  be  almost  a  national  dish  in  Italy. 

The  three  principal  forms  of  bread  made  from  corn  meal 
are  hoe-cake,  johnny-cake,  and  brown  bread ;  the  formulas 
for  which  are  given  on  the  following  page.^ 

In  the  ''  Cotton  Belt "  of  the  United  States  corn  furnishes 
the  principal  bread  food,  rather  than  wheat.  In  other  sec- 
tions of  the  United  States  —  also  in  Europe  —  corn  meal  is 
used  in  proportions  varying  from  5  to  50  per  cent  in  a  variety 
of  bread  and  pastry  foods,  where  a  coarse  flour  is  desirable. 

1  Maine  Bui.  131,  p.  139. 


252 


CORN   CROPS 


Johnny- 
cake 
Grams 

Brown 
Bread 
Grams 

Hoe-cake 
Grams 

Corn  meal 

Flour  (wheat) 

Salt 

Sugar      

Baking  powder 

Molasses 

Water 

Milk 

100.0 
100.0 

5.0 
10.0 

4.4 

150.0 

100.0 

100.0 

4.0 

4.4 
40.0 

200.0 

100.0 

5.0 
5.0 

400.0 

References  on  corn  as  food :  — 

Food  Value  of  Corn  and  Corn  Products.  Farmers'  Bui.  298. 
1907.  Indian  Corn  as  Food  for  Man.  Maine  Bui.  131. 
1906. 


CHAPTER  XXI 
SHOW  CORN 

The  culture  and  characteristics  of  show  corn  deserve 
special  discussion. 

180.  Corn  shows,  in  common  with  poultry  and  live  stock 
shows,  serve  a  practical  purpose,  in  so  far  as  they  sustain 


Fig.  87.  —  Show  ears  of  Boone  Countj^  White.    A  typical  white  variety 
of  the  corn-belt. 

interest,  and  ^rve  as  a  rallying  ground  for  those  interested 
in  production. 

On  the  other  hand,  show  corn  is  not  necessarily  the  best 
type  to  grow  or  most  productive,  and  farmers  have  often 

253 


254 


CORN   CROPS 


s^sgg, 


i^f?^^^^: 


^^^•^95^5: 


'^lllis 


made  the  mistake  of  bujdng  it 
to  plant  under  conditions  not 
suited  to  that  type  of  corn. 

Usually  show  corn  is  grown 
under  the  most  favorable  con- 
ditions of  climate  and  soil. 
There  are  certain  regions,  such 
as  southern  Indiana,  central 
Illinois,  and  Missouri  River 
bottom  land,  where  corn  appar- 
ently attains  a  perfection  in 
type  not  possible  under  aver- 
age conditions. 

Our  study  of  acclimatiza- 
tion developed  the  importance 
of  growing  seed  corn  under 
conditions  similar  in  soil  and 
climate  to  the  region  where 
it  is  to  be  used  as  seed.  This 
makes  it  doubtful  whether 
corn  grown  under  the  most 
favorable  environment  is  best 
adapted  for  average  conditions. 

The  future  of  corn  shows 
does  not  rest  so  much  on 
practical  considerations  as 
aesthetic.  A  sound,  perfect 
ear  of  corn  is  beautiful,  artis- 
tic, and  pleasing  to  the  senses. 
The  plant  on  which  it  grew  is 
interesting  in  the  same  way. 

Fig.  88.  —  A  typical  ear  of  show  corn. 
Ried's  yellow  dent. 


^^ 


SHOW  CORN  255 


The  ear  also  represents  the  largest  and  most  interesting 
crop  in  the  United  States,  and  the  principal  means  of  sup- 
port of  many  millions.  So  long  as  men  admire  perfect 
ears  of  corn,  the  corn  show  will  last. 

181.  Show  corn  is  judged,  on  the  basis  of  degree  of 
perfection  exhibited,  both  in  soundness  and  general  sym- 
metry, uniformity,  and  beauty.  It  must  be  perfectly 
sound  and  matured,  and  free  from  signs  of  deterioration 
due  to  disease  or  improper  care. 

The  characters  of  show  corn  may  be  grouped  in  two 
classes,  as  those  that  pertain  to  soundness  and  maturity 
and  those  that  pertain  to  perfection  in  symmetrx-asd  uni- 
formity.  The  first  class  is  of  practical  value  and  applies 
in  the  judging  of  all  seed  corn.  The  second  class  of  points 
cannot  be  said  to  be  important  to  consider  in  seed  selection. 

182.  Maturity  is  judged  by  the  general  plumpness  and 
development  of  the  kernels.  If  the  kernels  are  loose  on  the 
cob,  or  unduly  shrunken  at  tip  or  crown,  the  ear  probably 
did  not  mature  properly. 

183.  Soundness  is  judged  principally  by  the  vitality 
of  germs  and  strength  of  germination.  Good  germs 
should  be  plump,  of  a  texture  similar  to  good  cheese,  and 
no  signs  of  discoloring.  Any  variation  from  this  can 
usually  be  seen,  but  it  is  not  always  possible  to  judge 
the  viability  by  examination  alone.  A  germination  test 
is  sometimes  necessary  to  determine  this  point. 

Fanc^  characters  pertain  to  the  perfection  and  symmetry 
of  development  of  all  parts  of  the  ear,  as  butts,  tips,  rows, 
kernels,  etc. 

184.  Standards  of  perfection  have  been  adopted  in  re- 
gard to  a  few  of  the  best-knoAvn  varieties,  but  at  present 
these  standards  are  not  regarded  very  much  by  corn 
judges,  but  rather  a  universal  standard  has  come  to  be 


256 


CORN  CROPS 


recognized,  which  is  appUed  to  all  exhibits,  more  or  less 
regardless  of  variety. 

For  dent  corn  the  following  standards  are  generally 
accepted : 

Shape  of  ear.  —  Cylindrical  or  nearly  so.  The  circum- 
ference should  be  about  three-fourths  the  length. 

Size  of  ear.  —  The  standard  size  of  large  dent  varieties 
is  ten  inches  in  length  and  seven  and  one-half  inches  in 


Fig. 


Ideal  butt  and  tip  ends  of  dent  corn.     Note  the  regular  size  of 
kernels  in  both  cases. 


circumference;  of  medium  dents,  eight  inches  long  and 
six  inches  circumference. 

Rows.  —  The  rows  should  be  straight,  and  each  row 
be  full  length  of  ear  and  extend  well  over  butt  and  tip. 
Short  or  irregular  rows  are  regarded  as  imperfections. 

Butt  ends.  —  The  butt  end  should  be  well  rounded, 
not  flat.  The  shank  should  be  about  one-half  the  diam- 
eter of  cob.  If  smaller,  the  ear  is  liable  to  fall  off  the  stalk ; 
and  if  larger,  the  ear  is  more  difficult  to  husk. 

Tip  of  ears.  —  The  rows  should  extend  in  a  regular 
way  well  over  the  tip.     Only  a  small  exposure  of  cob  at 


SHOW  CORN 


257 


the  tip  end  is  allowed.     Full  depth  of  grain  should  extend 
almost  to  the  very  tip  of  the  ear. 

Type  of  kernel.  —  A  good  kernel  of  large  dent  corn 
should  be  about  seven-eighths  inch  in  length  and 
three-eighths  in  width,  if 
an  eighteen-row  ear,  but 
narrower  if  more  rows. 
The  kernels  should  fit  close 
from  tip  to  crown,  being 
somewhat  keystone  shaped. 
The  kernels  should  be  fairly 
thick,  averaging  in  the  row 
about  six  kernels  to  the 
inch.  The  kernel  tip  should 
be  full  and  square ;  the  germ, 

large,    plump,   and    of    good      Fig.    90.  —  Cross-section    of    very 
rnlnr  and  tpxtiirp  deep-kerneled  type  of  dent  corn 

color  ana  texture.  commonly  known  as  hackberry. 


GROWING   SHOW    CORN 

185.  The  seed  must  come  from  a  good  show  strain 
with  many  generations  of  selection  for  type.  The  soil 
should  be  naturally  good  corn  soil,  and  everything  done 
to  put  the  soil  in  perfect  condition,  by  proper  rotation, 
manuring,  and  tillage.  The  soil,  however,  can  be  too  rich 
in  nitrogen  for  best  results,  as  the  plant  is  then  inclined  to 
run  too  much  to  stalk  rather  than  ear.  The  soil  should 
be  rich  in  available  minerals.  Good  show  ears  seldom 
come  from  the  portion  of  field  where  the  growth  is  rankest, 
but  rather  from  a  part  where  growth  of  stalk  is  normal 
but  ears  large. 

The  rate  of  planting  should  be  rather  thin,  about  two- 
thirds  normal  stand. 


258 


CORN  CROPS 


The  crop  should  be  handled  so  as  to  insure  a  rapid 
normal  growth  throughout  the  season  without  a  check. 


Fig.  91.  — An  example  of  prolific  corn. 


CHAPTER  XXII 
SWEET  CORN  OR  SUGAR  CORN 

By  Albert  E.  Wilkinson 

Sweet  corn  is  grown  chiefly  as  a  vegetable  for  table 
use,  although  the  stover  is  usually  harvested  as  forage  for 
stock.  Sometimes  sweet  corn  is  planted  as  a  silage  or 
forage  crop.  The  development  of  sweet  corn  has  been  dis- 
cussed in  another  place  (page  79). 

VARIETIES   AND    TYPES 

186.  Sweet  corn  may  be  divided  into  about  the  same 
general  classes  and  types  as  field  corn.  The  height  of 
the  stalk  varies  from  three  to  ten  feet  and  the  number  of 
rows  on  the  ear  from  eight  to  twenty.  Practically  all 
common  colors  are  found.  The  time  from  planting  to 
maturity  varies  from  65  to  110  days. 

187.  As  mentioned  before  (page  23)  sweet  corn  is  any 
one  of  the  starch  corns  (flint,  dent,  or  flour  corn)  that  has 
lost  its  faculty  of  coverting  sugars  into  starches;  hence, 
a  large  part  of  its  carbohydrate  material  remains  in  the 
form  of  sugar,  although  some  starch  may  be  developed. 

Sweet  corn  culture  is  most  extensive  in  the  vicinity  of 
large  cities,  where  it  is  grown  as  a  market-garden  and 
truck  crop,  and  in  regions  where  it  is  grown  as  a  can- 
ning crop. 

188.  According  to  the  latest  census,  1910,  the  number 
of  farms  reported  as  growing  sweet  corn  in  the  United 

259 


260 


CORN   CROPS 


States  was  48,514,  the  number  of  acres,  178,224,  the  value 
of  the  product,   $5,936,419.     New  York  leads  with  the 

number  of  farms 
reporting,  having 
6,584,  the  number 
of  acres  being 
23,739,  and  the 
value  of  the  prod- 
uct $942,023.  Penn- 
sylvania is  second 
in  number  of  farms, 
4,896  reporting 
sweet  corn.  The 
second  place  in 
number  of  acres, 
however,  is  with  Il- 
linois, 19,976  acres. 
Illinois  is  also  sec- 
ond in  the  value  of 
the  product,  having 
$558,746.  Ohio  is 
third  in  the  number 
of  farms,  having 
4,591.  Maryland 
is  third  in  the  num- 
ber of  acres,  report- 
ing 18,387  acres  de- 
voted to  the  crop. 
In      total      value, 

An  ear  of  green  corn,  at  proper  stage  NeW    Jersey     takes 
^ortaUonse.  ^^.^^      pj^^^^     ^.^j^ 

$557,708.     Around  the  large  cities  of  the  northern  part 
of  the  United   States,  large  areas  are  devoted   to   the 


Fig.  92. 


SWEET  CORN  OR    SUGAR   CORN 


261 


262  CORN  CROPS 

production  of  sweet  corn  for  immediate  consumption. 
Farther  back  and  in  several  of  the  states,  in  particular 
Illinois,  Indiana,  Iowa,  Maine,  Maryland,  New  York, 
and  Ohio,  the  great  canning  industry  is  developed,  and 
large  acreage  is  devoted  to  the  growing  of  sweet  corn  for 
canning. 

VARIETIES 

The  varieties  can  be  classified  under  three  heads : 
(1)  canning,  (2)  commercial  or  market  garden  varieties, 
and  (3)  home  garden  varieties. 

The  principal  canning  variety  is  a  late  corn,  Stowell 
Evergreen.  Country  Gentleman  is  also  used  to  a  large 
extent  among  the  canners.  In  the  Maine  canneries,  a 
corn  known  as  Clark's  is  used.  This  is  a  corn  which  has 
been  developed  by  the  large  canning  houses,  and  the 
seed  is  grown  in  that  section.  Farther  west,  the  Hickox 
is  used  to  a  considerable  extent,  while  Trucker's  Fa- 
vorite and  Evergreen  are  considered  desirable  in  some 
sections. 

189.  The  commercial  varieties  may  be  subdivided  into 
three  or  four  divisions.  Among  the  early  varieties  are 
Cory,  Adams  Early,  Early  Maine,  Peep  o'  Day,  Aristo- 
crat ;  medium  earlies,  Metropolitan,  Golden  Bantam,  and 
other  golden  corns.  Honey,  Quincy  Market,  and  Crosby; 
late  varieties,  Country  Gentleman,  Stowell  Evergreen, 
Late  Mammoth  Hickox,  Black  Mexican. 

In  the  home  garden  varieties,  quality  is  of  first  impor- 
tance. The  custom  is  either  to  plant  early  and  late  corn, 
or  one  high-class  variety  such  as  Golden  Bantam  every  two 
weeks  for  both  early  and  late.  A  not  unusual  sequence 
of  varieties  is :  Cory,  Crosby,  Quincy  Market,  Country 
Gentleman,  and  Stowell  Evergreen. 


SWEET  CORN   OR   SUGAR   CORN  263 


SEED 

190.  The  canning  men  as  a  rule  raise  their  own  seed, 
or  have  it  raised  on  private  farms  by  contract.  In  raising 
seed  it  is  important  to  keep  it  free  from  contamination  with 
other  varieties,  especially  with  field  corn.  When  a  sweet 
corn  field  is  within  a  quarter  of  a  mile  of  field  corn,  the 
sweet  corn  ear  is  likely  to  have  kernels  that  resemble  the 
field  corn,  due  to  wind-blown  pollen.  All  blocks  of  seed 
corn  should  be  far  enough  apart  to  protect  against  cross- 
pollination.  The  commercial  grower  or  market-gardener 
very  often  produces  his  own  seed. 

In  some  cases  the  seed  has  been  maintained  on  the  same 
farm  for  many  years.  Some  of  these  growers  have  suc- 
ceeded by  careful  selection  in  developing  desirable  early 
types  suited  to  their  needs  and  as  a  result  are  able  to 
market  their  product  very  early  and  secure  the  highest 
price. 

191.  The  home  gardener  must  depend  practically  from 
season  to  season  upon  the  product  that  he  can  buy  of 
the  seedsman.  If  the  seedsman  is  one  who  practices 
good  methods  of  breeding  and  selecting  his  corn,  the  re- 
sultant seed  is  high  class.  If  the  seed  is  grown  under  con- 
tract and  care  is  given,  the  results  are  satisfactory.  When 
a  large  firm  is  responsible,  it  is  reasonable  to  expect  that 
the  corn  will  come  true  to  name. 

192.  Breeding  and  selecting  sweet  corn  offers  an  interest- 
ing field  for  investigation.  As  explained  before  (page  105) 
the  sweet  corn  grain  type  and  starchy  grain  do  not  blend 
in  hybridizing.  The  sweet  corn  type  of  grain  is  a  reces- 
sive. This  makes  it  possible  to  cross  sweet  corn  with  any 
type  of  starchy  corn  and,  by  selecting  sweet  corn  grains 
from  the  hybrids,  have  pure  sweet  corns  at  once  which 


264 


CORN  CROPS 


may  be  combined  with  many  or  all  the  characters  of  the 
starchy  parent. 

SELECTING   AND    CURING   SWEET   CORN 

193.  Methods  of  selecting  seed  sweet  corn  vary  with 
different  growers.  One  way  that  has  been  found  satis- 
factory is  herewith  given. 

For  many  years  it  has  been  the  custom  to  select  for 
home  planting  a  number  of  ears  having  characteristics 


Fig.  94.  —  Handy  rack  for  drying  seed  corn. 


most  desirable.  Earliness  is  maintained  only  by  saving 
the  earliest  ears  from  the  early  corn,  and  from  these  earliest 
ears  a  small  number,  known  as  ''double  extra,"  are  set 
aside  for  the  breeding-plat.  In  selecting  these  double 
extra  ears,  it  is  important  to  note,  not  only  size,  length 
of  grain,  and  length  of  cob,  but  also  the  character  of  the 


SWEET   CORN   OR   SUGAR    CORN  265 

corn  for  quality,  as  denoted  by  its  translucent  appearance. 
It  is  important  to  practice  rigid  selection,  that  is,  not  only 
to  have  a  great  many  of  the  right  kind  of  ears,  but  to  plant 
none  or  the  wrong  kind  in  the  breeding  plat  or  near  it. 

One  of  the  most  important  factors  in  the  sweet  corn 
industry  is  the  proper  curing  of  the  seed  ears.  Sweet 
corn  molds  and  ferments  more  easily  than  field  corn. 
This  greatly  injures  germination.  Freezing  before  curing 
also  injures  germination. 

194.  Drying  seed  corn  by  fire  heat  is  often  practiced  in 
seed  houses  equipped  for  the  work,  but  is  not  the  most  prac- 
ticable method  on  a  small  scale.  Corn  thrown  in  a  large 
pile  with  or  ^vithout  the  husk  on  will  develop  heat  enough 
inside  of  twenty-four  hours  to  injure  the  germ,  sour  the 
cob,  and  discolor  the  grain.  Sweet  corn  cut  and  shocked 
up  like  field  corn  will  sour  before  it  dries,  unless  the  weather 
be  both  cool  and  dry  enough  before  winter  to  escape  in- 
jury by  freezing.  Corn  left  on  the  stalk  untouched  until 
the  husk  opens  will  be  greatly  discolored  and  injured  by 
a  spell  of  hot,  damp  weather.  If,  however,  the  ears  be 
husked  out  on  a  dry  day  and  allowed  to  lie  a  few  hours 
exposed  to  the  direct  rays  of  the  sun,  the  organisms  which 
cause  fermentation  are  killed  by  the  sunshine,  and  a  layer 
of  impervious  matter  is  formed  over  the  butt  end  of  the 
cob,  which  makes  it  more  difficult  for  fermentation  to 
start. 

The  following  method  of  curing  sweet  corn  seed  is 
recommended  :  When  the  husk  is  dead  and  loose  on  the 
ear,  wait  for  a  bright,  clear  day,  begin  early  in  the 
morning,  and  cut  do\ATi  a  small  piece  of  corn,  throwing 
into  piles.  The  same  forenoon,  when  the  sun  is  shining 
bright,  husk  it  out  as  rapidly  as  possible,  throw  the  corn 
into  small  piles  on  the  ground,  tie  the  fodder  into  bundles, 


266  COBN   CROPS 

and  set  it  up  in  small  shocks.  Before  night,  haul  in  the 
corn  and  put  it  on  a  slatted  floor.  The  floor  is  made  of 
lath  one  inch  thick  by  two  inches  wide,  spaced  one  inch 
apart.  The  corn  is  taken  up  in  baskets,  and  each  basket 
is  turned  upside  down  on  the  slats,  and  taken  off  carefully, 
so  that  the  ears  are  left  like  a  pile  of  ''  jack-straws,"  crossed 
in  every  direction,  many  of  them  standing  in  a  nearly  verti- 
cal position.  Each  basketful  of  corn  is  emptied  in  a  fresh 
place,  and  when  all  is  done  the  slats  are  covered  with  corn 
about  a  foot  deep,  but  so  loosely  arranged  that  there  is  no 
obstruction  to  the  passage  of  air  between  the  ears.  In 
this  position  it  dries  very  quickly  and  may  be  put  into 
barrels  as  soon  as  all  moisture  is  out  of  the  cob.  Each 
barrel  may  be  covered  with  a  piece  of  cloth  held  down  by 
the  top  hoop,  and  then  the  barrel  turned  on  its  side. 

This  plan  applies  more  to  the  regions  with  humid  fall 
weather  than  to  those  regions  in  the  West  where  fall  weather 
is  dry. 

GROWING   SWEET   CORN   FOR   CANNING 

195.  Canning  corn  is  grown  under  contract  with  the  firm 
in  many  corn-growing  regions.  The  canning  company 
sends  out  a  contract  similar  to  the  following :  — 

Sweet  corn  agreement 

(Place),  (Date) 
This  agreement  made  with  the Canning  Com- 
pany, by  which  I  hereby  agree  to  plant  and  raise  for  said 
Company acres  of  sweet  corn,  the  same  to  be  de- 
livered at  factory  from  time  to  time  as  required  by  said 
Company,  in  proper  condition  for  canning  during  the 
season  of  191- ;  for  which  said  Company  agrees  to  pay 
seven  dollars  per  ton,  said  Company  to  furnish  me  at  their 
factory  seed  corn  at  the  proper  time  for  planting.     For 


SWEET  CORN  OR   SUGAR   CORN  267 

said  seed  corn  I  agree  to  pay  said  Company  two  dollars 
per  bushel  on  or  before  the  first  day  of  October,  191-,  or 
from  the  proceeds  of  corn  delivered  on  this  contract.  I 
further  agree  (1st)  to  plant  said  corn  in  three  different 

plantings,  first  planting, acres,  to  be  planted  early 

in  May ;  second  and  third  plantings, acres,   to  be 

planted  the  last  of  May  or  the  first  week  in  June,  or  after 
each  preceding  planting  is  well  up.  (2d)  Not  to  let  any 
corn  become  heated  or  damaged  by  remaining  in  bulk 
too  long,  and  to  deliver  said  corn  the  day  it  is  picked. 
(3d)  To  make  a  short  snap  close  to  the  ear.  (4th)  It 
is  further  agreed  that  the  corn  covered  in  this  contract 
shall  not  be  paid  for  till  October  first,  191-.  (5th)  That 
corn  must  not  be  planted  near  field  corn  unless  it  be  white 
field  corn,  as  mixed  yellow  corn  is  unfit  for  canning.  In 
case  of  destruction  of  the  cannery  by  the  elements,  said 
Company  not  to  be  held  liable  for  damages  on  this  contract. 

(Signed)     (The  Company) 
(Signed)     (The  Farmer) 

196.  Rotation.  —  It  is  often  to  the  advantage  of  the 
growers  to  plant  their  cannery  corn  crop  in  rotation  with 
other  crops.  It  is  desirable  that  the  corn  can  be  planted 
following  a  sod,  especially  if  on  this  sod  from  eight  to  ten 
tons  of  stable  manure  are  applied  and  plowed  under.  From 
experiments,  sweet  corn  is  found  to  be  greatly  benefited 
by  deep  plowing  in  some  soils.  If  choice  of  soil  is  obtain- 
able, the  piece  of  ground  that  will  give  the  most  satisfac- 
tory results  is  a  gravelly  or  a  sandy  loam,  especially  if 
there  is  some  chance  of  having  humus,  such  as  sod  or 
manure.  The  corn  is  generally  planted  with  a  machine, 
either  one-  or  two-row  corn  planter ;  and  at  the  same  time, 
some  growers  apply  from  three  to  five  hundred  pounds  of 


268  CORN   CROPS 

a  3-8-5  fertilizer  formula,  or  if  the  manure  is  deficient,  up 
to  1000  to  1200  pounds  of  fertilizer  of  the  same  formula. 
In  some  cases,  growers  raising  sweet  corn  place  not  only 
the  above  amount  of  manure  on  their  ground,  but  some- 
times more,  and  add  the  larger  amount  of  fertilizer,  as 
well. 

197.  Distance  between  the  rows  in  planting  is  from 
30  to  42  inches.  Sometimes  the  distance  between  the 
hills  in  the  rows  is  but  24  inches,  and  other  times  it  will 
extend  to  36  inches.  The  general  custom  is,  with  the 
smaller-growing  varieties,  to  lessen  the  distance,  whereas 
with  the  large-growing  varieties,  such  as  Stowell,  the  dis- 
tance is  increased  so  that  each  plant  may  have  a  normal 
amount  of  space  for  full  development.  More  seed  is  gen- 
erally planted  in  the  hill  than  is  required,  from  five  to 
eight  seeds  being  dropped  in  each.  Later,  this  corn  is 
thinned  to  three  or  four  stalks  to  the  hill.  By  this  pro- 
cess the  three  or  four  best  developed  plants  are  allowed 
to  remain. 

The  weeder  is  used  soon  after  the  seed  is  planted,  or  a 
fine-tooth  harrow.  When  the  corn  has  broken  ground, 
the  weeding  is  generally  discontinued,  and  a  fine-tooth 
cultivator  used.  This  may  be  a  one-row  or  a  two-row 
cultivator.  The  general  plan  at  first  in  cultivation  is  to 
till  rather  deeply,  especially  in  the  middle  of  the  row 
between  the  plants,  later  tilling  more  shallow.  The 
corn  plant  requires  constant  tillage  and  a  good  soil 
mulch  for  its  best  development  and  conservation  of  the 
moisture.  Hand  hoeing  would  be  necessary  if  weeds  were 
troublesome,  especially  if  the  plot  was  not  check-rowed. 
However,  there  are  some  men  that  go  to  the  extra  care 
of  check-rowing  their  corn,  and  cultivating  in  two  direc- 
tions, then  omitting  the  hand  hoeing.     It  may  be  an  ad- 


SWEET  CORN  OR   SUGAR   CORN  269 

vantage  to  go  through  with  a  hand  hoe,  because,  at  the 
same  time  that  hoeing  is  performed,  sucker  growths  may 
be  removed  from  the  corn,  thereby  improving  the  quahty 
and  size  of  the  ears.  When  it  is  seen  that  the  horse  and 
machine  in  cultivating  are  injuring  the  corn,  this  work 
is  discontinued,  and  the  corn  is  allowed  to  grow  without 
farther  attention. 

About  the  time  of  marketing,  the  factories  generally 
send  a  man  to  the  field  to  instruct  the  farmer  just  when  to 
bring  the  corn  to  the  factory.  In  the  different  sections, 
there  is  some  difference  of  opinion  as  to  when  the  corn 
should  be  harvested  for  the  factory  and  just  how.  In 
general,  the  corn  should  be  delivered  to  the  factory  as  soon 
as  possible  after  breaking  from  the  stalk.  There  are  some 
companies  that  desire  the  corn  broken  in  the  morning  and 
carted  immediately  to  their  factories.  As  stated  in  a 
number  of  reports  received  from  canners,  they  did  not 
desire  the  growers  to  pick  the  corn  in  the  late  afternoon 
and  allow  this  to  stand  in  the  wagons  over  night,  owing 
to  heating  of  the  corn. 

In  harvesting,  the  ear  is  broken  from  the  plant  so  that 
there  is  very  little  or  no  stub  left  on  the  base,  and  the 
unnecessary  husks  as  well  are  taken  off.  However,  no 
extra  attention  or  care  is  given  at  this  period.  The  corn 
may  be  gathered  in  baskets  or  in  boxes,  and  immediately 
emptied  in  a  wagon.  When  the  wagon  is  full,  it  is  taken 
to  the  factory  and  there  weighed,  if  sold  at  so  much  a  ton 
green  weight. 

198.  Thirty-five  dollars  is  a  fair  return  for  an  acre,  ex- 
clusive of  the  value  of  the  fodder,  as  well  as  the  husk  and 
the  cob,  which  the  growers  can  take  back  to  their  farms. 
The  average  returns  for  sweet  corn  to  the  acre  are  between 
three  and  four  tons.     Example :     On  good  Iowa  land,  a 


270  CORN  CROPS 

farmer  will  average  with  a  good  stand  about  three  tons 
per  acre.  Some  years  the  yield  will  be  as  high  as  four  and 
one-half  tons.  The  price  varies,  but  for  large  Evergreen 
corn  from  six  to  seven  dollars  is  received  per  gross  ton 
of  corn  with  the  husks  on,  and  for  smaller  varieties  the 
price  is  from  $7.50  to  $8.50  per  gross  ton.  Other  states 
report  different  yields  and  different  prices  for  their  corn. 
Very  much  depends  on  the  cannery,  the  methods  em- 
ployed, and  several  other  factors.  The  above  are  average 
figures. 

Besides  the  corn  gro^vn  for  the  canneries  under  con- 
tract, canneries  often  grow  a  large  acreage  of  corn  for  their 
own  use.  The  work  there  is  conducted  similarly  to  that 
of  the  men  who  contract  with  them.  They  plant  their 
com  at  different  periods,  so  that  it  may  extend  over  a 
long  season  and  they  may,  by  so  planting,  be  able  to 
keep  the  factory  busy  throughout  the  season. 

MARKET   SWEET   CORN 

Commercial  corn  growing  for  consumption  in  the  green 
stage  may  be  classed  as :  market-garden  sweet  corn  grow- 
ing, which  embraces  the  extremely  early  and  a  small 
amount  of  the  main  season  crop ;  and  truck  growing  sweet 
corn,  which  never  embraces  the  extremely  early  crop,  but 
only  the  main  and  late  crops. 

199.  The  market-garden  crop  is  generally  gro^\Ti  on 
high-priced  land  near  the  centers  of  population.  The 
soil  is  generally  in  the  best  condition  and  of  the  typical 
market-garden  type,  a  sandy  loam  well  supplied  with 
humus,  and  improved  each  year  by  applications  of  ma- 
nure, sometimes  as  high  as  40  tons  to  the  acre.  Besides 
the  heavy  applications  of  manure,  some  market-gardeners 
use  large  quantities  of  commercial  fertilizer.     The  general 


SWEET  CORlSf  OR   SUGAR   CORN  271 

idea  among  them  is  that  in  order  to  get  an  early  crop  of 
sweet  corn,  which  is  the  one  that  brings  the  highest  money, 
they  should  have  food  for  the  plant  quickly  available. 

200.  From  six  to  eight  kernels,  in  some  cases  more,  are 
planted  in  each  hill.  For  the  early  varieties,  the  hills  may 
be  as  close  as  one  foot.  From  fifteen  to  eighteen  inches  is 
more  nearly  the  average  distance  between  hills  in  the  row. 
The  distance  between  rows  varies  from  twenty-four  to 
thirty  inches.  The  cleanest  culture  is  given,  and  irriga- 
tion is  practiced  in  some  cases. 

Market-gardeners,  by  their  intensive  methods  of  plant- 
ing, are  able  to  place  corn  on  the  market  from  ten  days 
to  two  weeks  earlier  than  men  living  a  little  farther  back 
from  the  centers  of  population,  and  practicing  less  inten- 
sive methods.  In  cultivating  the  corn,  especially  with  the 
hoe,  suckering  is  generally  practiced. 

Cultivation  is  continued  thoroughly  and  as  along  as 
possible,  the  horse  being  muzzled  when  it  is  found  that 
injury  results.  If  the  corn  is  not  growing  to  suit,  slight 
applications  of  fertilizer,  especially  nitrate  of  soda  100  to 
150  pounds  per  acre,  are  made.  ^ 

In  planting  the  early  and  main  season  and  late  varie- 
ties, some  planters  practice  sowing  the  seed  at  the  same 
time,  and  allowing  the  difference  in  the  period  of  maturity 
to  bring  the  crop  in  at  the  proper  time.  Other  growers 
prefer  to  plant  their  corn  at  intervals  of  ten  days  to  two 
weeks.  This  latter  seems  to  be  the  most  practicable 
method. 

201.  Marketing.  —  As  soon  as  the  ear  is  at  the  right 
stage  for  harvesting  it  is  broken  from  the  plant  and  placed 
in  baskets  or  boxes,  immediately  taken  to  the  shed,  and 
there  repacked.  In  the  eastern  markets,  especially  in  New 
England,  the  corn  is  packed  in  boxes,  a  certain  definite 


272  CORN   CROPS 

number  of  ears  in  each  box.  For  New  York  and  Phila- 
delphia and  through  the  North  and  West,  ears  are  sold 
by  the  hundred  in  sacks  or  hampers.  This  is  less  satis- 
factory. It  is  not  a  pleasing  pack  or  one  that  attracts 
attention.  The  bushel  box  is  more  practical,  more  up  to 
date  and  the  corn  carries  better.  In  the  sack  the  corn 
has  been  kno\vn  to  heat  because  too  much  was  placed 
together. 

202.  The  first  corn  coming  to  the  market  sells  for  thirty 
to  forty  and  in  some  cases  fifty  cents  a  dozen.  It  then 
steadily  declines  until  it  reaches  eight  and  even  six  cents 
a  dozen.  If  a  man  has  a  retail  route  and  has  corn  through- 
out the  season,  he  usually  maintains  a  high  average  price. 
Some  men  never  sell  for  less  than  fifteen  cents  throughout 
the  season  from  their  retail  wagons. 

203.  The  bulk  of  the  main  crop  and  the  late  crop  are 
grown  a  little  farther  back  from  cities  on  less  expensive 
land,  and  under  less  intensive  methods.  The  rows  and 
hills  are  generally  a  little  farther  apart,  three  feet  to  forty- 
two  inches  between  rows,  and  from  thirty  to  thirty-six 
inches  between  hills  in  the  row.  Fertilizer  up  to  a  thou- 
sand or  twelve  hundred  pounds  is  applied  with  the  corn. 
The  corn  is  commonly  planted  on  sod  ground,  this  being 
usually  spring  plowed.  Clean  culture  is  practiced  in  the 
early  part  of  the  season.  The  corn  is  generally  harvested 
the  same  as  for  the  market-gardening.  When  grading  and 
packing  is  necessary,  the  ears  should  be  of  uniform  size 
and  about  the  same  degree  of  maturity.  Better  prices 
can  be  thus  secured.  The  corn  is  usually  shipped  to 
commission  houses,  to  wholesale  stores,  to  clubs  and  hotels. 
Gross  returns  of  $100  an  acre  ^vill  make  a  crop  of  corn 
profitable.  As  high  as  $350  the  acre  has  been  received 
from  sweet  corn. 


SWEET  CORN  OR   SUGAR   CORN  273 


FORCING   SWEET   CORN 

204.  Forcing  under  glass  has  been  practiced  for  com- 
mercial corn  growing.  Experiments  have  been  tried,  es- 
pecially in  New  England.  The  Early  Minnesota,  Crosby, 
Early  Cory,  Adams  and  other  varieties  have  been  used  for 
forcing  with  more  or  less  success.  A  summary  of  sugges- 
tions is  given  here. 

205.  The  requirements  for  forcing  corn  under  glass  are 
practically  the  same  as  those  for  forcing  other  warm- 
weather  plants,  such  as  tomatoes,  melons,  cucumbers,  and 
egg-plants,  —  a  day  temperature  of  70°  to  80°  and  a  night 
temperature  of  60°  to  70°  being  required,  the  atmosphere 
in  the  house  to  be  rather  moist  during  the  first  period  of 
the  corn's  growth,  but  when  pollen  begins  to  fall,  the  at- 
mosphere being  dry.  The  crop  should  be  marketed  before 
July  first,  in  order  to  be  remunerative.  Extra  early 
varieties  maturing  in  from  65  to  83  days  from  seed  are  to 
be  used.  The  corn  may  be  started  in  pots,  either  paper 
or  clay,  a  few  seed  in  each  pot,  and  later  transplanted 
where  it  is  to  stand  in  the  greenhouse.  Inter-cropping 
with  radishes,  lettuce,  or  spinach  may  be  practiced,  to 
utiUze  all  space  in  the  greenhouse  to  the  best  advan- 
tage. The  distance  between  rows  should  be  18  inches, 
and  between  hills  in  the  row  9  inches.  Suckers  are  very 
common  in  a  crop  of  this  kind,  and  these  should  be  re- 
moved. The  principal  pests  in  the  greenhouse  are  rats 
and  mice.  They  bother  both  by  digging  out  the  seed 
and  by  attacking  the  matured  ear,  spoihng  it  for  sale. 
Poisoning  or  destroying  these  pests  should  be  performed 
before  the  crop  is  planted. 

206.  Forcing  corn  in  hot  beds  or  cold  frames  very  early 
in  the  season,  allowing  it  to  mature  in  these  beds,  is  a 


274  CORN  CROPS 

practical  method.  In  this  way,  corn  may  be  obtained 
for  consumption  in  the  month  of  June  when  the  price 
is  very  high.  The  general  conditions  of  groAvth  are  the 
same  as  those  for  greenhouse  work.  The  spacing  between 
the  corn  is  the  same.  Careful  attention  as  to  ventilation 
and  watering  should  be  given.  The  pollination  in  the 
hotbed  or  cold  frame  ^vill  be  looked  after  by  the  natural 
elements,  but  in  the  greenhouse  it  is  advisable  to  shake 
the  corn  plant  slightly  when  the  pollen  is  ripe. 

A  still  later  method  of  forcing  has  been  practiced  on  a 
limited  acreage  near  some  cities,  and  that  is  starting  the 
corn  in  paper  pots  or  other  receptacles.  Two  or  three 
seeds  are  planted  in  each  pot,  allo\\ang  the  corn  to  grow 
from  four  to  six  inches,  and  then  transplanting  the  corn  to 
the  garden  after  the  weather  conditions  have  settled.  The 
corn  at  this  time  should  be  four  to  six  inches  high.  The 
roots  have  not  suffered  by  being  pruned,  and  the  plant 
will  continue  its  growth.  This  method  has  been  tried 
both  in  the  East  and  the  Middle  West,  and  where  the 
demand  warrants,  has  proved  satisfactory. 

SWEET   CORN   IN   THE   HOME    GARDEN 

207.  In  the  home  garden  the  aim  should  be  to  have  a 
liberal  and  constant  supply  of  sweet  corn.  The  variety 
should  correspond  with  the  personal  taste  of  the  individual 
gardener  or  consumer.  It  is  doubtful  whether  the  extra 
early  corns  will  answer  the  demands  of  the  individual 
home  gardeners,  as  they  lack  somewhat  in  quality. 

The  home  'gardener  does  not  have  a  great  choice  of  soil 
for  the  grooving  of  sweet  corn.  The  garden  may  be  heavy 
clay  or  light  loam.  In  either  case  the  principal  treatment 
should  be  liberal  applications  of  stable  manure.  Some  per- 
sons apply  a  little  commercial  fertilizer,  but  this  is  the  ex- 


SWEET  CORN  OR   SUGAR   CORN  275 

ception  rather  than  the  rule.  No  fertilizer  is  needed  if  the 
garden  has  plenty  of  manure.  Sweet  corn  in  the  home 
garden  may  be  grown  under  the  methods  described  for 
commercial  growing.  Transplanting  corn  from  hotbeds 
is  a  feasible  method  for  the  home  garden,  especially  for 
early  corn.  Inter-cropping  of  the  corn,  in  the  earliest 
stages  when  planted  from  seed,  would  be  practical.  Such 
crops  as  radishes,  spinach,  lettuce,  and  even  beans  can  be 
grown  in  the  home  garden,  utilizing  apparently  waste  space, 
which  later  is  necessary  for  the  full  development  of  the 
corn. 


PART  II 
SORGHUMS 


CHAPTER  XXIII 
THE  SORGHUM   PLANT 

Sorghum  {Andropogon  Sorghum  var.  vulgaris,  Hackel, 
A.  Sorghum,  Brot.,  Sorghum  vulgare,  Pers.)  is  generally 
conceded  to  have  been  originally  derived  from  the  well- 
known  wild  species,  Andropogon  halepensis,  Brot. 

The  wild  species  is  found  abundantly  in  all  tropical 
and  subtropical  parts  of  the  Old  World  and  has  been  in- 
troduced into  the  Western  Hemisphere,  where  it  is  now 
well  distributed  in  both  North  and  South  America  between 
the  parallels  of  latitude  thirty  degrees  north  and  south  of 
the  equator. 

209.  Andropogon  halepensis  is  generally  known  in  the 
United  States  as  Johnson-grass.  Johnson-grass  is  a  coarse- 
growing  perennial,  with  strong  underground  rootstocks  by 
means  of  which  it  spreads  rapidly  and  is  very  persistent, 
being  regarded  generally  as  a  bad  weed. 

Sorghum  differs  from  the  wild  form  in  that  it  is  larger- 
growing,  that  it  produces  more  seed,  that  certain  forms 
have  abundant  sweet  juice,  and  that  no  form  is  perennial 
or  has  persistent  rootstocks.  However,  there  are  forms  of 
Andropogon  halepensis  that  are  annual  and  without  the 
persistent  rootstocks,  an  example  being  the  variety  known 
as  "  Soudan  grass."  The  wild  form  is  somewhat  vari- 
able, having  certain  types  parallehng  in  their  variations 
the  cultivated  forms. 

279 


280 


CORN  CROPS 


GEOGRAPHICAL   ORIGIN 

210.  Hackel  ^  states  that  the  cultivated  forms  had  their 
origin  in  Africa,  but  BalP  beheves  that  they  also  had 
an  independent  origin  in  India  as  well. 

The  early  history  of  sorghum  culture  is  unknown,  but 


Fig.  95.  —  Plant  of  sorghum.     (After  Fuchs,  1542.) 

1  Hackel,  Edward.     The  True  Grasses,  p.  59. 

2  Ball,   Carleton  R.     U.  S.   Dept.  Agr.,   Bur.   Plant  Indus.,   Bui. 
175,  pp.  9-10. 


THE  SORGHUM  PLANT  281 

there  is  good  evidence  that  it  was  an  important  crop  in 
both  Africa  and  South  Asia  hundreds  of  years  before  the 
Christian  Era.  A  reference  to  millet  in  the  Bible 
(600  B.C.)  probably  refers  to  sorghum.  (Ezek.  x.  4.  The 
word  millet  is  translated  ''  dochan "  in  the  original 
Hebrew  text,  a  word  still  in  use  in  Arabic  for  various 
forms  of  sorghum.)  Sorghum  is  well  adapted  to  meet  the 
needs  of  a  primitive  agriculture.  The  seeds  provide 
human  food,  while  the  plant  furnishes  abundant  fodder  for 
animals.  Under  favorable  conditions  the  plant  will  run 
wild  to  some  extent,  and  is  better  able  to  care  for  itself 
than  any  other  of  our  important  cultivated  plants. 

Sorghum  is  at  present  the  most  important  cereal  food 
of  the  native  people  of  Africa,  and  is  a  very  important 
crop  through  the  southern  half  of  Asia.  There  are  no 
statistics  of  the  world's  production  of  sorghum.  The 
United  States  crop  is  estimated  at  about  3,000,000  acres 
and  that  of  India  at  25,000,000.  The  crop  of  Africa  and  of 
Asia  Minor  should  approximate  that  of  India. 

BOTANICAL   CLASSIFICATION 

Order  —  Graminece. 

Tribe  —  Andropogonece. 

Genus  —  Andropogon. 

Species  —  A.  Sorghum  var.  vulgare. 

211.  Ball  ^  has  suggested  the  following  classification  as  a 
key  to  the  principal  groups  of  sorghum :  — 
I.  Pith  juicy. 

A.  Juice  abundant  and  very  sweet. 

1.  Internodes  elongated ;  sheaths  scarcely  overlapping; 
leaves  12-15  (except  in  Amber  varieties)  ;  spike- 
lets  eUiptic-oval  to  obovate,  2.5-3.5  mm.  wide; 
seeds  reddish  brown.  I.  Sorgo 

1  Ball,  Carleton  R.  U.  S.  Dept.  Agr.,  Bur.  Plant  Indus.,  Bui.  175,  p.  8. 


282  CORN   CROPS 

B.  Juice  scanty,  slightly  sweet  to  subacid. 

1.  Internodes    short;      sheaths     strongly     overlapping; 

leaves  12-15 ;  peduncles  erect ;  panicles  cylin- 
drical;  spikelets  obovate,  3-4  mm.  wide; 
lemmas  awnless.  II.  Kafir. 

2.  Internodes   medium ;     sheaths   scarcely   overlapping ; 

leaves  8-11 ;  peduncles  mostly  inclined,  often 
recurved ;  panicles  ovate ;  spikelets  broadly 
obovate,    4.5-6    mm.    wide ;     lemmas    awned. 

VII.  Milo. 
II.  Pith  dry. 

A.  Panicle  lax,  2.5-7  dm.  long;    peduncles  erect;    spikelets 

eUiptic-oval  or  obovate,  2.5-3.5  mm.  wide; 
lemmas  awned. 

1.  Panicle  4-7  dm.  long;    rachis  less   than  one-fifth  as 

long  as  the  panicle. 
a.  Panicle  umbelliform,   the  branches  greatly  elon- 
gated,   the    tips    drooping ;     seeds    reddish,    in- 
cluded. III.  Broom-corn. 

2.  Panicle    2.5-4    dm.    long;     rachis    more    than    two- 

thirds  as  long  as  the  panicle. 

a.  Panicle  conical,  the  branches  strongly  drooping ; 

glumes  at  maturity  spreading  and  involute  ;  seeds 
white,  brown,  or  somewhat  buff.         IV.  Shallu. 

b.  Panicle  oval  or  obovate,  the  branches  spreading; 

glumes  at  maturity  appressed,  not  involute ; 
seeds  white,  brown,  or  reddish.        V.  Kowliang. 

B.  Panicle   compact,    1-2.5   dm.    long ;    peduncles   erect    or 

recurved ;  rhachis  more  than  two-thirds  as  long 
as  the  panicle. 

1.  Spikelets  elliptic-oval   or  obovate,  2.5-3.5  mm.  wide; 

lemmas  awned.  V.  Kowliang. 

2.  Spikelets  broadly  obovate,  4.5-6  mm.  wide. 

a.  Glumes  gray  or  greenish,  not  wrinkled ;  densely 
pubescent ;  lemmas  awned  or  awnless ;  seeds 
strongly  flattened.  VI.  Durra. 

h.  Glumes  deep  brown  or  black,  transversely 
wrinkled  ;  thinly  pubescent ;  lemmas  awned  ; 
seeds  slightly  flattened.  VII.  Milo. 


THE  SORGHUM  PLANT  283 

212.  Technical  description.  —  The  plant  varies  in  height 
from  a]:>out  4  feet  (dwarf  Milo)  to  12  or  15  feet  high  in 
some  of  the  tropical  forms. 

Panicle,  or  "  head,"  varies  in  shape  from  the  small, 
compact  "  sumac  "  type,  in  which  the  rachis  is  almost 
as  long  as  the  panicle,  through  the  looser  and  more  branch- 
ing forms  of  the  Collier  type,  in  which  the  rachis  is  about 
one-half  that  of  the  panicle,  to  the  broom-corn  type,  in 
which  the  rachis  is  only  one-fifth  the  length  of  the  branches. 

Seeds.  —  The  shape  of  seed  varies,  from  round  in  the 
Kafir,  Kowliang,  and  Shallu,  to  somewhat  pear-shaped  in 
certain  of  the  sweet  sorghums,  somewhat  flattened  in  Milo, 
and  decidedly  flat  in  the  Durras.  The  seed  coat  of  all 
dark-colored  varieties  has  a  decidedly  astringent  taste, 
due  to  the  presence  of  tannin.  The  amount  of  tannin 
seems  to  vary  with  the  color,  being  greatest  in  the  black- 
seeded  and  dark  red  varieties,  very  little  in  yellow  seeds, 
and  there  being  none  in  white  seeds.  The  astringency 
apparently  has  no  ill  effect  except  as  it  affects  flavor,  the 
dark-seeded  grain  not  being  so  desirable  for  stock  food  on 
this  account. 

Stems.  —  Stems  vary  not  only  in  height  (from  4  to  15 
feet),  but  also  in  relative  thickness.  The  Amber  variety 
is  slender,  with  stems  less  than  1  inch  in  diameter,  while  in 
the  Gooseneck  variety  the  stems  are  1  to  2  inches  thick. 
In  slender-stemmed  varieties  the  nodes  are  usually  long, 
about  12  inches ;  while  in  the  stouter-stemmed  varieties 
the  tendency  is  toward  short  nodes,  as  in  the  Sumac, 
the  average  length  being  8  or  9  inches. 

Juices.  —  Stems  are  designated  as  juicy  or  dry.  The 
actual  water  content  of  the  green  stems  does  not  differ  so 
much  in  the  two  cases,  the  green  stems  being  80  to  90  per 
cent  water.     In  the  juicy-stemmed  varieties  the  juice  is 


284  CORN  CROPS 

easily  extracted  by  crushing  and  pressing.  An  ordinary 
roller  cane  press  will  extract  50  to  60  per  cent  of  the  juice. 

Not  all  juicy  sorghums  are  sweet,  but  practically  all 
the  very  juicy  varieties  are.  The  sugar  content  of  the 
juice  in  sweet  sorghums  varies  from  10  to  18  per  cent. 

Leaves.  —  The  leaves  of  the  sorghums  are  strong  and 
are  especially  well  adapted  to  withstand  the  rather  dry 
and  often  hot  winds  that  prevail  in  semiarid  regions. 
In  periods  of  protracted  drought  the  leaves  assume  a 
rather  erect  position,  rolling  together  to  a  considerable 
degree  in  a  way  that  appears  to  protect  against  exces- 
sive evaporation.  All  the  very  drought-resistant  forms, 
as  the  Milo  and  Durra  types,  are  rather  scanty-leaved ; 
the  leaves  being  about  eight  to  ten  in  number,  rather 
broad  and  short,  and  rather  coarse  in  texture. 

Tillers.  —  All  varieties  of  sorghum  seem  to  produce 
tillers  abundantly.  These  appear  at  the  lower  joints  of 
the  stem.  The  buds  that  develop  into  tillers  may  re- 
main more  or  less  dormant  when  conditions  for  growth  are 
unfavorable,  ready,  however,  to  develop  at  the  first  favor- 
able opportunity.  Fertile  soil  and  thin  planting  favor 
their  development.  Certain  varieties,  however,  seem  to 
produce  two  or  more  tillers  normally,  the  tillers  starting 
almost  as  soon  as  the  main  stem,  and  it  is  only  under  the 
very  thickest  planting  that  they  are  suppressed. 

It  sometimes  occurs,  when  the  first  part  of  the  season  is 
dry  and  unfavorable,  that  the  main  stem  may  become 
stunted ;  if  late  rains  come,  the  tillers  will  often  grow  much 
taller  than  the  main  stalk.  The  tillers  are  later  in  matur- 
ing and  are  considered  undesirable  when  the  crop  is 
grown  for  grain  or  sirup ;  but  they  are  usually  desirable 
when  the  crop  is  grown  for  forage,  as  they  no  doubt  in- 
crease the  yield  of  fodder. 


THE  SORGHUM  PLANT  285 

When  sorghum  plants  are  cut  off,  tillers  usually  spring 
up  at  once.  In  the  South  two  crops,  and  even  three 
crops,  may  be  cut  from  the  same  roots.  In  regions  of 
very  mild  winters  the  roots  of  certain  varieties  will  live 
over,  giving  a  crop  the  second  year. 

Branches.  —  Branches  come  from  latent  buds  on  the 
upper  part  of  the  stem  as  tillers  do  from  the  lower  nodes. 
The  same  conditions  that  favor  tillering  favor  the 
development  of  branches.  The  first  branch  appears 
from  the  topmost  node,  the  second  from  the  next,  and  so 
on  down,  in  order ;  under  very  favorable  conditions  and 
thin  planting,  four  or  five  branches  may  develop.  Each 
branch  bears  a  small  head,  similar  to  the  main  head  but 
later  in  maturing. 

Branches  are  considered  undesirable,  and  the  usual 
plan  is  to  plant  the  sorghum  thick  enough  so  that  there 
will  be  neither  tillering  nor  branching. 

Roots.  —  The  Kansas  station  made  a  study  of  Kafir 
corn  and  sweet  sorghum  roots  in  comparison  with  corn  and 
other  field  crops.  The  roots  of  Kafir  corn  were  found  to  be 
finer  and  more  fibrous  than  corn  roots  under  the  same  con- 
ditions. A  few  of  the  longer  Kafir  roots  penetrated  to  a 
depth  of  3  feet,  but  most  of  them  were  confined  to  the 
upper  18  inches,  filling  the  soil  to  this  depth  with  a  fine 
network  of  roots ;  while  corn  under  the  same  conditions 
fully  occupied  the  upper  30  inches  with  roots  (see  Fig.  12, 
page  27),  sending  its  deepest  roots  about  4  feet.  The 
sweet  sorghum  roots  were  somewhat  intermediate  in  char- 
acter, but  resembled  the  Kafir  more  than  the  corn  roots.  ^ 

The  distribution  of  roots  indicates  that  the  sorghums 
draw  their  nutrients  from  the  surface  soil  much  more 
than  corn. 

1  Kans.  Agr.  Exp.  Sta.,  Bui.  127,  pp.  207-208.     1904. 


286  CORN  CROPS 

PHYSIOLOGY   OF   THE    SORGHUMS 

213.  In  general,  the  physiology  and  nutrition  of  sor- 
ghum are  similar  to  those  of  corn,  which  has  been  set  forth 
(page  38).  The  most  interesting  physical  phenomenon  of 
sorghum  from  an  economic  standpoint  is  its  general  re- 
sistance to  drought  and  to  the  climatic  conditions  that 
prevail  in  dry  climates. 

Drought  resistance.  —  The  drought  resistance  of  sor- 
ghum is  well  established.  Its  ability  to  yield  in  a  dry 
climate  is  apparently  not  due  to  a  deep  root  system  or  to 
any  other  adaptation  of  the  root  system  so  far  reported. 
Neither  does  it  seem  to  be  due  to  a  low  water  requirement, 
as  the  few  tests  made  on  this  point  indicate  that  quite  as 
much  is  required  per  pound  of  dry  weight  as  for  Indian 
corn  or  for  other  crops  not  particularly  adapted  to  dry 
conditions. 

The  success  of  sorghum  under  semiarid  conditions 
seems  to  depend  on  two  qualities,  not  found  developed 
to  so  great  a  degree  in  other  crops :  (1)  The  high  resist- 
ance of  leaves  to  injury  from  hot,  dry  weather.  The  non- 
saccharine  groups,  especially,  will  withstand  dry  and  hot 
climatic  conditions  that  would  wither  most  vegetation  be- 
yond recovery.  (2)  The  plants  have  the  faculty  of  becom- 
ing almost  dormant,  so  far  as  growth  is  concerned,  for 
long  periods  during  severe  drought.  During  such  periods 
the  leaves  roll  and  tend  to  assume  an  upright  position. 
This,  no  doubt,  reduces  evaporation  from  the  leaves  and 
affords  protection  to  the  younger  leaves  and  the  seed 
head.  The  plant  may  remain  in  this  condition,  apparently 
without  growth,  for  several  weeks,  far  beyond  the  endur- 
ance of  most  cultivated  plants.  With  the  coming  of  rain, 
growth  will  usually  be  renewed  with  vigor.     If  the  main 


THE  SORGHUM  PLANT  287 

stalk  has  been  much  stunted,  tillers  will  often  grow  up  at 
once  and  become  taller  than  the  main  stalk.  While 
tillers  do  not  usually  produce  a  good  seed  crop,  they  are 
satisfactory  as  forage. 

REPRODUCTION 

214.  The  sorghums  are  all  ^^perfect-flowered" — the 
pollen  and  ovary  being  in  the  same  flower,  instead  of  in 
separate  flowers  as  in  corn.  This  is  the  principal  botanical 
distinction  between  the  tribe  Maydece,  to  which  corn 
belongs,  and  the  tribe  Andropogonece,  to  which  sorghum 
belongs. 

FERTILIZATION 

215.  All  sorghums  are  adapted  to  both  self-fertilization 
and  wind  fertilization.  Apparently,  self-fertilization  is 
normal  in  the  sorghums,  and  is  in  no  way  injurious  as  it  is 
in  corn  (page  107).  In  developing  pure  strains  of  sorghum 
it  has  been  found  practicable  to  cover  the  heads  with 
bags  before  blooming,  thus  securing  complete  self-fertili- 
zation. 

NATURAL   CROSSING 

216.  Under  normal  field  conditions  more  or  less  crossing 
takes  place.  Regarding  this  point  BalP  makes  the  fol- 
lowing statement :  "  Just  to  what  extent  cross-fertiliza- 
tion takes  place  under  normal  field  conditions,  it  is,  of 
course,  impossible  to  say.  However,  in  the  case  of  ad- 
jacent rows  of  different  varieties,  flowering  on  approxi- 
mately the  same  dates,  as  high  as  50  per  cent  of  the  seed 
produced  on  the  leeward  row  has  been  found  to  be  cross- 
fertihzed.  It  is  probable  that  in  a  fairly  uniform  field 
of   any   given   variety   a   similar   percentage   of   natural 

1  Ball,  Carleton  R.    American  Breeders'  Association,  Vol.  VI,  p.  193. 


288  CORN   CROPS 

crossing  takes  place.  Many  writers  have  stated  that 
such  cross-poUination  occurs  also  at  very  long  distances, 
but  this  seems  to  be  less  conclusively  proved.  Probably 
a  distance  of  8  to  10  rods  to  leeward  is  the  maximum  at 
which  appreciable  hybridization  occurs."  Ball  also  states 
that  the  pollen  is  mostly  shed  during  the  early  morning 
hours,  when  the  winds  are  usually  at  lower  velocities 
than  later  in  the  day. 

Crossing  of  types.  —  All  the  different  types  of  sorghum, 
as  sweet  sorghums,  non-saccharine  types,  and  broom-corns, 
cross  readily.  (See  Fig.  115.)  Broom-corn  growers  must 
exercise  sorrie  care  in  keeping  their  seed  stocks  pure,  in 
regions  where  other  varieties  of  sorghum  are  grown. 

CLIMATE    AND    SOILS 

217.  The  entire  botanical  genus  {Andropogon) ,  made  up 
of  hundreds  of  species,  is  found  growing  principally  in 
wide-open  plains  regions.  Hackel  ^  states,  "  the  species 
prefer  dry  places,  especially  savannas." 

Climatic  requirements 

Temperature  and  sunshine.  —  Sorghum,  like  corn,  is  a 
plant  of  tropical  origin,  varieties  of  which  have  been 
adapted  to  temperate  climates.  Like  corn,  it  requires 
abundant  sunshine  and  warm  weather,  being  very  sensitive 
to  cool  nights.  At  high  elevations  where  nights  are  gen- 
erally cool,  sorghum  seldom  does  well  even  when  the  days 
are  warm  and  sunshiny. 

Humidity  and  rainfall. — While  both  corn  and  sorghum 
require  sunshine  and  warmth,  they  apparently  differ 
somewhat  as  to  humidity,  corn  preferring  regions  of  high 

1  Hackel,  Edward.     The  True  Grasses,  p.  57. 


THE  SORGHUM  PLANT  289 

humidity  such  as  prevail  in  the  Mississippi  valley,  and 
sorghum  preferring  regions  of  dry  air  such  as  prevail  in 
the  Great  Plains  region  of  the  upper  Missouri  River 
valley  and  southward. 

The  above  general  difference  may  be  due  in  part  to 
selection  of  varieties.  Sorghum  being  of  tropical  origin 
and  widely  distributed,  certain  varieties  flourish  in  very 
humid  regions  of  Africa.  Certain  varieties  of  the  sweet 
sorghums  grow  well  in  the  Carol inas  and  Gulf  States, 
where  both  rainfall  and  humidity  are  high. 

While  certain  sorghums  do  well  under  humid  conditions, 
the  ability  of  all  sorghums  to  remain  more  or  less-  dormant 
during  periods  of  drought,  and  to  renew  growth  with  the 
return  of  rain,  has  qualified  the  crop  for  adaptation  to  dry 
climates.  For  centuries  sorghums  have  been  grown  and 
adapted  to  dry  conditions  in  the  Old  World  as  they  are 
being  further  adapted  in  the  United  States.  The  result 
is  that  the  principal  varieties  of  sorghum  under  cultivation 
prefer  a  drier  and  warmer  climate  than  is  required  by  the 
corn  crop,  although  no  doubt  varieties  of  sorghum  could 
be  found  equally  adapted  to  humid  regions.  The  above 
conclusion  applies  with  more  truth  to  the  grain  sorghums 
(Kafirs  and  Durras)  than  to  the  sweet  sorghums  or  broom- 
corns. 

Soil  requirements 

218.  The  sorghums  are  adapted  to  a  wide  range  of  soils, 
but  they  prefer  a  medium-weight  loam  to  very  light  or  very 
heavy  soils.  The  grain  sorghums  are  apparently  more 
sensitive  in  this  respect  than  the  sweet  sorghums.  Sor- 
ghums for  forage  are  often  grown  on  poor  land,  not  only 
because  they  produce  more  forage  than  any  other  crop 
under  such  conditions,  but  also  because  the  stems  are 
finer  than  when  grown  on  heavy  land, 
u 


290  CORN  CROPS 

219.  Effect  on  the  land.  —  The  sweet  sorghums  sown 
thickly  have  the  reputation  of  being  "  hard  on  the  land." 
Grain  sorghums  planted  thin  seem  to  have  the  same  effect 
also,  in  lesser  degree.  All  millets  have  the  same  reputation. 
No  very  satisfactory  explanation  for  this  has  been  ad- 
vanced. When  the  effect  is  noted  it  is  most  marked  on  the 
first  crop  following,  and  less  marked  afterward,  usually 
completely  disappearing  in  one  or  two  years.  The  effect 
is  most  marked  on  small  grain  and  less  on  intertilled 
crops. 

As  the  sorghum  roots  are  rather  concentrated  in  the 
upper  layers  of  soil,  it  is  possible  that  this  soil  is  very  much 
exhausted  of  available  fertility.  There  is  some  reason  to 
believe  that  sorghums  may  exhaust  available  fertility  to 
lower  limits  than  do  other  crops.  It  is  not  known  whether 
sorghums  have  a  toxic  effect  on  the  soil. 

The  injurious  effect  when  noted  is  considered  only 
temporary,  and  farmers  in  general  do  not  consider  it  a 
serious  drawback  to  sorghum  culture. 

220.  Alkali  resistance.  —  Sorghum  is  often  said  to  be 
alkali-resistant.  It  is  not  resistant  in  the  same  sense 
as  are  many  native  alkali  plants,  but  at  least  it  is  one  of 
the  best  of  our  cultivated  plants  to  succeed  on  land  rich 
in  alkali. 

SORGHUM   TYPES 

221.  A  common  grouping,  based  principally  on  the 
economic  use  of  the  crop,  is  (a)  Saccharine  sorghums,  (6) 
Non-saccharine  sorghums,  (c)  Broom-corns. 

A.  Saccharine  sorghums.  Those  having  an  abundant  sweet 
juice.  Cultivated  at  one  time  principally  for  sirup  manu- 
facture, but  now  principally  as  a  forage  plant.  Commonly 
known  as  "  sorghum."  I.  Sorgo. 


THE  SORGHUM  PLANT  291 

B.  Non-saccharine  sorghums, 

1.  Pith  contains  a  scant  juice,  which  varies  from  slightly 

sweet  in  some  varieties  to  subacid  in  others.  Grown  princi- 
pally for  the  grain,  but  also  has  forage  value.     II.   Kafir. 

III.  Milo. 

2.  Pith  dry. 

(a)    Grown  principally  for  the  grain  and  forage. 

II.   Kafir. 

VI.   Durra. 

IV.   Shallu. 

V.   Kowliang. 

(6)    Grown  for  the  bush,  no  value  as  forage. 

VII.   Broom-corn. 

The  economic  discussion  of  sorghums  will  follow  the 
above  grouping. 


292 


CHAPTER  XXIV 

THE  SACCHARINE  SORGHUMS 

Sweet  Sorghums 

222.  This  group  of  sorghums  is  usually  designated  as 
sweet  sorghums,  or  ''sugar"  sorghums.  They  are  quite 
distinct  from  the  non-saccharine,  grain  sorghums  in  having 
a  juicy  stem  containing  a  high  percentage  of  sugar  and  in 
producing  a  rather  light  seed  crop. 

Early  culture.  —  The  sweet  sorghums  have  never  been 
cultivated  extensively  in  the  Old  World,  where  the 
sorghums  have  been  cultivated  more  for  seed  than  for 
forage  —  the  non-saccharine  forms  being  more  productive 
for  the  former  purpose.  The  sweet  sorghums  seem  to  have 
been  kept  in  cultivation  principally  for  the  sweet  canes, 
which,  however,  were  not  manufactured  but  were  peeled 
and  the  juice  was  expressed  by  chewing.  Almost  no  sweet 
sorghum  is  raised  in  North  Africa  or  in  India ;  it  has  been 
kept  in  cultivation  in  China  and  South  Africa,  however, 
though  only  in  a  small  way. 

223.  Introduction  into  the  United  States.  —  The  first 
recorded  introduction  into  the  United  States  was  from 
China  in  1853,  by  way  of  France,  and  the  plant  was  known 
at  first  as  "  Chinese  Sorgo."  This  was  a  loose-panicled 
sorghum,  from  which  have  been  derived  most  of  our 
cultivated  varieties  of  Amber  sorghum.  "  Our  Early 
Amber  is  said  to  have  originated  in  1859  as  a  sport  in  a 
field  of  Chinese  sorgo  growing  in  Indiana."  ^ 

1  Ball,  Carleton  R.     I.e.,  p.  25. 
293 


294  CORN   CROPS 

A  collection  of  sixteen  varieties  of  sorghum  brought 
from  Natal,  South  Africa,  to  Europe  in  1854  and  from 
Europe  to  this  country  in  1857,  included  several  sweet 
sorghums,  from  which  have  been  derived  our  compact- 
headed  tj^pes  such  as  Orange,  Sumac,  and   Gooseneck. 

Development  of  culture  in  the  United  States.  —  While 
sweet  sorghum  has  remained  a  secondary  crop  in  the  Old 
World,  it  had  a  rather  rapid  development  in  the  United 
States,  owing  to  the  belief  that  it  would  become  a  great 
sugar-  and  sirup-producing  crop.  In  1857  the  United 
States  Patent  Office  distributed  275  bushels  in  small  lots 
to  farmers ;  The  American  Agriculturist  distributed  to  its 
subscribers  1600  pounds  in  small  packages,  and  the  next 
year  34,500  pounds  in  the  same  way.  At  this  time  exten- 
sive experiments  were  being  made  with  it  in  Europe  for 
the  manufacture  of  sugar,  and  later  the  United  States 
Government  ^  conducted  an  elaborate  series  of  experiments 
for  the  same  purpose.  With  the  development  of  sugar 
beets  at  this  time  a  better  source  of  crystallized  sugar  was 
found,  and  the  plan  of  using  sorghum  for  this  purpose  was 
abandoned. 

First  grown  as  a  sirup  crop.  —  However,  sorghum  was 
found  to  be  a  cheap  source  of  home  made  sirup  and  it  was 
more  or  less  grown  for  this  purpose  in  every  rural  com- 
munity. Local  ''  sorghum  mills  "  were  very  common  dur- 
ing the  eighties  in  the  Central  and  Western  States.  Dur- 
ing the  dry  years  in  the  early  eighties,  and  again  during 
the  general  drought  of  1892-1894  in  Nebraska,  Kansas, 
and  southward,  sorghums  of  all  kinds  were  found  to  with- 
stand drought. 

There  are  no  available  data  on  acreage  of  sweet  sor- 
ghum, but  the  data  on  Kafir  corn  (page  304)  indicate  the 

1  See  U.  S.  Dept.  Agr.,  Bur.  Chem.,  Buls.  26,  40,  etc. 


THE   SACCHARINE   SORGHUMS 


295 


umED  staks 

/4^0S<>THOU5ANO 

'enuoim 


F:g.  97. — Production  of  torg-i-'---i  sirup  middle  of  last  century 


umno  STATES 

/6.97S  THOUJANO 


Fig.  98.  —  Production  cf  sirup  at  close  of  century. 


296  CORN   CROPS 

increase  of  sweet  sorghum  as  the  acreage  of  the  two  crops 
of  late  years  is  about  equal.  Beginning  with  1890,  the 
acreage  has  continued  to  increase  up  to  the  present 
time. 

224.  How  the  crop  is  utilized.  —  In  the  Central  States 
east  of  the  Mississippi  River,  these  sorghums  have  been 
cultivated  principally  since  1865  for  the  manufacture  of 
sirup.  The  extent  of  sirup  manufacture  for  the  census 
years  is  as  follows  :  — 

Year  Gallons 

1860 -6,749,123 

1870 16,050,089 

1880 28,444,202 

1890 424,235,219 

1900 •     .     .    16,972,783 

The  principal  States  in  sirup  manufacture  for  the  last 
three  decades  have  been  Tennessee,  Missouri,  and  Ken- 
tucky, but  the  industry  has  shown  a  rapid  decrease  in 
all  these  States.  In  only  one  State,  North  Carolina,  has 
it  shown  a  notable  increase.  Figures  97  and  98  show 
graphically  the  distribution  at  two  periods. 

225.  As  a  forage  crop.  —  West  of  the  Missouri  River 
and  southward  in  the  Great  Plains  region,  the  culture  of 
sweet  sorghum  is  principally  as  a  forage  crop.  It  is  an 
important  forage  crop  in  the  drier  parts  of  Kansas, 
Oklahoma,  Nebraska,  and  Texas.  The  use  of  sweet 
sorghum  as  a  forage  crop  has  developed  since  1880. 

226.  Classification  of  sweet  sorghums.  —  The  following 
classification  is  adapted  from  Ball :  — 

A.  Peduncle  and  panicle  erect. 

1.  Panicle  loose,  open,  branches  spreading  to  horizontal 
or  drooping ;  rachis  two-thirds  as  long  to  equahng 
the  panicle. 


THE  SACCHARINE  SORGHUMS  297 

Empty  glumes  black,  hairy.  I.  Amber. 

Empty  glumes  black,  smooth.  II.  Minn.  Amber. 

Empty  glumes  red.  III.  Red  Amber. 

Empty  glumes  light  brown.  IV.  Honey. 

Rachis  less  than  one-half  the  length  of  the  panicle  :  — • 
Panicle  light,  drooping  branches,  seeds  orange  to  red. 

V.  Collier. 
Panicle  heavy,  seeds  orange.         VI.  Planter's  Friend. 
2.  Panicle  close,  compact. 

Empty  glumes  equal  to  seeds,  seed  red.     VII.  Orange. 

Empty  glumes  half  as  long  as  the  small  seeds,  seeds 

dark  red.  VIII.  Sumac. 

Empty  glumes  narrow.  IX.  Sapling. 

B.  Peduncle  recurved  (goosenecked)  or  sometimes  erect. 

Panicle  black,  glumes  awned.  X.  Gooseneck. 

The  three  varieties  that  have  had  most  extensive  cul- 
tivation are  Amber,  Orange,  and  Sumac. 

227.  Amber,  being  the  earliest  of  the  three  (90  to 
100  days),  has  been  practically  the  only  variety  grown 
in  the  northern  limits  of  sorghum  culture  —  that  is, 
north  of  Kansas  and  the  Ohio  River — ^and  has  been 
most  popular  in  Kansas,  the  leading  sorghum-growing 
State. 

Amber  grows  about  5  to  7  feet  tall,  with  8  to  10  leaves, 
being  neither  so  tall  nor  so  leafy  as  the  other  two  varieties. 
The  seed  head  is  usually  black  and  is  loose  or  spreading, 
though  it  is  somewhat  variable  in  this  respect.  A  number 
of  selections  have  been  made,  the  best  known  of  which 
are :  Minnesota  Amber,  which  differs  only  in  minor 
details ;  Red  Amber,  the  heads  of  which  are  red  instead  of 
black  but  which  is  otherwise  similar  ;  and  Folger's  Early,  a 
strain  said  to  be  especially  desirable  for  sirup  production. 
The  various  strains  of  Amber  sorghum  have  been  popular 
for  forage  because  of  the  rather  slender  stems  and  early 


298 


COBN  CEOPS 


maturity,  these  qualities  facilitating  the  curing  and  im- 
proving the  quality  of  forage. 


Fig.  99.  —  Amber  sorghum. 


228.  Orange  sorghum  is  two  to  three  weeks  later  in 
maturing  (100  to  125  days)  than  is  Amber.  It  is  about  12 
inches  taller,  the  stalk  is  heavier  and  the  nodes  are  shorter, 


THE  SACCHARINE  SORGHUMS 


299 


and  the  plant  is  more  leafy.  The  variety  name  refers  to 
the  deep  orange  color  of  the  ripe  heads.  This  variety  is 
excellent  for  sirup  pro- 
duction and  it  makes 
a  heavy  yield  of  for- 
age, especially  on  good 
land.  However,  for 
cured  forage  farmers 
object  somewhat  to 
heavy  stalks,  as  they 
are  more  difficult  to 
handle  and  cure. 
Orange  sorghum  is 
second  in  popularity 
to  Amber  and  is  grown 
principally  from  Kan- 
sas southward. 

Collier  and  Coleman 
are  two  varieties  of 
the  Orange  sorghum 
t3i3e  which  are  so  sim- 
ilar to  it  that  for  all 
forage  purposes  they 
may  be  considered  the 
same.  The  Collier  is 
considered  the  better 
for  sirup-making. 

229.  Sumac  sor- 
ghum derives  its  name 
from   the   very   com-  t-      ,nn      ^  i, 

^  Fig,  100.  —  Orange  sorghum. 

pact   red    seed    head, 

resembling  the  seed  head  of  sumac.     It  is  somewhat  larger 

and  perhaps  later  than  Orange,  but  otherwise  similar  in 


300 


CORN   CROPS 


appearance  of  plant.  "  For  forty  years  this  has  been  the 
most  popular  variety  in  the  South,  especially  in  the  Pied- 
mont districts.  It  is  now  largely  grown  in  Texas  and 
Oklahoma  also." 

230.  Gooseneck  is  a  very  large, 
late-growing  variety,  adapted 
only  to  the  South.  Ten  to  fifty 
per  cent  of  the  heads  are  re- 
curved, or  '^goosenecked." 


LLU-^ 


Fig.  101.  —  Sumac  sorghum. 


Fig.  102.  —  Gooet'iieck  sorghum. 


CHAPTER  XXV 

THE  NON-SACCHARINE  SORGHUMS 

231.  The  non-saccharine  sorghums,  with  the  exception 
of  broom-corn,  are  often  called  grain  sorghums  because 
their  principal  value  is  as  grain  producers  rather  than  as 
producers  of  forage.  As  a  group,  they  constitute  the  most 
drought-resistant  grain  and  forage  crops  in  cultivation. 
The  five  principal  types  of  the  non-saccharine  sorghums 
are:  (1)  Kafir,  (2)  Durra,  (3)  Shallu,  (4)  KowHang,  (5) 
Broom-corn. 

Historical.  —  The  non-saccharine  sorghums  are  very 
generally  cultivated  throughout  Africa,  southwest  Asia, 
India,  and  Manchuria,  but  are  not  cultivated  extensively 
in  Europe.  In  general,  the  kafir  types  dominate  in  South 
Africa,  the  Durra  types  in  North  Africa,  southwest  Asia, 
and  India,  and  the  Kowliang  types  in  Manchuria.  Shallu, 
the  least  important  of  the  five  principal  groups,  is  grown  as 
a  winter  crop  in  India,  and  the  same  type  has  been  reported 
as  grown  in  a  limited  way  in  Madagascar  and  at  several 
points  in  Africa. 

232.  The  Durra  group  (spelled  also  dura,  durah,  doura, 
dhoura,  and  other  ways)  is  the  most  important  in  the  Old 
World.  It  should  be  noted,  however,  that  there  are  three 
general  groups  of  the  durra  sorghums,  only  one  of  which 
is  important  in  the  United  States  :  (1)  The  types  grown  in 
central  and  northeast  Africa  are  tall,  large-seeded,  and 
late-maturing,  furnishing  both  forage  and  grain ;   (2)  those 

301 


THE  NON-SACCHARINE  SORGHUMS  303 

of  North  Africa  are  shorter,  early,  comparatively  low  in 
forage  and  high  in  grain  production,  and  the  grain  is  flat 
and  of  medium  size ;  (3)  those  of  India  have  comparatively 
small  heads  and  seeds,  the  seeds  not  decidedly  flat ;  they 
produce  both  forage  and  grain,  but  are  too  large  and  late- 
maturing  for  culture  in  the  United  States. 

The  second  group  has  thus  far  furnished  most  of  the 
varieties  that  have  found  a  place  in  United  States  agricul- 
ture. The  probable  reason  is  that  grain  sorghum  could 
not  compete  with  maize  in  the  corn-growing  belt.  There 
was,  however,  a  distinct  demand  for  crops  adapted  to  the 
Great  Plains,  a  region  too  dry  for  the  culture  of  corn.  The 
sorghums  from  the  more  humid  regions  of  the  Old  World 
have  not  always  been  drought-resistant,  and  in  most 
cases  are  too  late  in  maturing.  Most  of  the  kafirs  and 
durras  meeting  the  requirements  of  drought  resistance 
and  a  short  maturing  season  have  come  from  the  drier 
regions  of  North  Africa  and  the  high  plains  of  South  Africa. 

233.  Introduction  in  the  United  States.  —  The  cultiva- 
tion of  non-saccharine  sorghums  dates  from  the  intro- 
duction of  White  Durra  and  Brown  Durra  into  California 
in  1874  and  the  introduction  of  kafir  in  1876,  but  they 
were  not  generally  distributed  until  about  ten  years  later. 

234.  Region  where  cultivated. — The  ^'grain  sorghums" 
are  cultivated  for  grain  and  for  forage.  They  are  not  so 
desirable  for  forage  alone  as  are  the  sweet  sorghums ;  the 
fodder  is  coarser  and  lacks  the  sweet  sugars  in  the  stem, 
being  less  palatable.  They  are  commonly  harvested  for 
both  grain  and  forage.  As  a  grain  crop  they  cannot  com- 
pete with  corn  in  the  regular  corn-growing  belt,  and  there- 
fore the  principal  grain-sorghum  belt  hes  just  west  of  the 
corn-growing  belt,  following  in  general  the  line  of  25- 
inch  rainfall  on  the  east  and  extending  west  to  the  Rocky 


304 


CORN  CROPS 


Mountains;    the  belt  includes  also  southern  California 
and  Utah.     The  accompanying  chart  ^  (Fig.  104),  prepared 


=  /r/FS/f   iVM£:/f£  M/LO  /S/V0yyy9  Sr/lPi.£  CfiOP. 

=  /1/fE/i  TO  i^H/CM  M/LO  IS  fi/Oiv  /to^^preo 

W////A    =  /IR£A  /Af  WWCH  THE  /!MPT'4e/UT)f  OF  M/LO  JS  B£/?lfG  rCST£p. 

Fig.  104.  — This  map  made  to  show  the  distribution  of  milo  ;  also  shows, 
approximately,  the  area  where  the  culture  of  all  sorghums  are  of  most 
importance. 

to  show  the  area  of  Milo  culture,  outlines  the  probable 
area  of  grain-sorghum  culture. 

235.  Statistics  of  culture.  —  It  is  not  possible  to  supply 
exact  figures  on  the  production  of  grain  sorghums.  The 
census  of  1909  gives  the  total  acreage  of  kafir  grown  for 
grain  as  266,513.  The  principal  States  reported,  and  their 
acreage,  were  as  follows :  — 

State  Acreage 

Kansas 154,706 

Oklahoma 63,455 

Texas 22,813 

California 20,218 

Total 261,192 

1  U.  S.  Dept.  Agr.,  Farmers'  Bui.  322,  p.  11. 


TEE  NON-SACCHARINE  SORGHUMS 


305 


Ninety-eight  per  cent  of  the  entire  acreage  was  produced 
in  four  States.  The  above  figures  do  not  include  that 
sown  as  forage.  From  the  Kansas  State  Board  of  Agri- 
culture, however,  we  have  data  for  the  census  year  show- 
ing 631,040  acres  sown  for  forage,  or  about  four  times  as 


Fig.  105.  —  Two  heads  of  Milo,  showing  good  and  poor  types. 


much  as  that  harvested  for  grain.  On  the  same  basis  for 
the  United  States  it  would  appear  the  the  non-saccharine- 
sorghum  acreage  for  1909  was  about  1,250,000  acres. 
The  acreage  has  since  increased  slightly  in  Kansas  and  to  a 
marked  degree  in  Oklahoma  and  Texas,  so  that  present 


306 


COEN  CROPS 


acreage  is  above  two  million  acres.     The  value  of  non- 
saccharine  sorghums  is  now  recognized,  and  with  the  im- 

AcREAGE,  Value,  and  Yield  of  Kafir,  Milo,  and  Corn  for 
THE  Years  1904  to  1909,  inclusive,  in  Kansas  and 
Oklahoma 


KANSAS 


Yield 

per 

Value 

Acre 

Chop  and  Year 

Acreage 

IN  Tons 

OR 

Bush- 
els 

Per  Ton 
or  Bushel 

Total 

Per  Acre 

Kafir: 

1904      .     .     . 

518,372 

3.04 

$3.19 

$5,041,546 

$9.70 

1905      .     .     . 

538,393 

3.24 

3.06 

5,352,810 

9.91 

1906      .     .     . 

548,497 

3.05 

3.01 

5,039,238 

9.18 

1907      .     .     . 

508,485 

2.94 

3.78 

5,658,860 

11.11 

1908      .     .     . 

630,096 

2.85 

3.82 

6,856,845 

10.89 

1909  ,  .     .     . 

636,201 

2.79 

4.02 

7,150,080 

11.21 

Average      . 

■ 

2.99 

3.48 

10.33 

Milo: 

1904      .     .     . 

7,166 

3.18 

3.22 

73,476 

10.24 

1905      .     .     . 

20,550 

2.84 

3.28 

190,974 

9.31 

1906      .     .     . 

17,563 

2.55 

3.26 

146,289 

8.31 

1907      .     .     . 

22,090 

2.72 

3.90 

234,686 

10.61 

1908      .     .     . 

55,255 

1.92 

4.85 

515,269 

9.31 

1909      .     .     . 

102,492 

1.97 

4.74 

959,259 

9.34 

Average 

2.53 

3.87 

9.52 

Corn: 

1904      .     .     . 

6,494,158 

20.3 

.39 

50,713,955 

7.81 

1905      .     .     . 

6,799,755 

28.0 

.36 

68,718,584 

10.11 

1906      .     .     . 

6,584,535 

28.4 

.35 

65,115,203 

9.25 

1907      .     .     . 

6,809,012 

21.3 

.43 

63,040,743 

9.26 

1908      .     .     . 

7,057,535 

21.3 

.55 

82,642,462 

11.71 

1909     .     .     . 

7,711,879 

19.1 

.57 

83,066,905 

10.77 

Average      . 

23.1 

.44 

9.83 

THE  NON-SACCHARINE  SORGHUMS 


307 


Acreage,  Value,  and  Yield  of  Kafir,  Milo,  and  Corn  for 
THE  Years  1904  to  1909,  inclusive  in  Kansas,  and 
Oklahoma 


OKLAHOMA 


Crop  and  Year 

Acreage 

Yield 

PER 

Acre 
IN  Tons 

OR 

Bush- 
els 

Valtje 

Per  Ton 
or  Bushel 

Total 

Per  Acre 

Kafir: 

1904  .     .     . 

1905  .     .     . 

1906  .     .     . 

1907  .     .     . 

1908  .     .     . 

1909  .     .     . 

334,948 
297,286 
269,218 
371,405 
400,047 

9.79 
12.72 
16.10 
13.50 

9.20 

$0.40 
.40 
.34 
.58 
.46 

$1,312,204 
1,512,318 
1,465,937 
2,881,032 
2,548,200  1 

$3.92 
5.08 
5.44 

7.77 
6.36 

Average 

12.26 

.44 

5.71 

Milo: 

1904 

1905  .     .     . 

1906  .     .     . 

1907  .     .     . 

1908  .     .     . 

1909  .     .     . 

138,608 
122,347 
131,366 
145,096 

20.06 
17.82 
13.30 
12.55 

.40 
.40 
.65 
.33 

1,112,602 

870,767 
1,142,098 
757,565  2 

8.02 
7.12 
8.64 
5.22 

Average     . 

15.93 

.45 

7.25 

Corn: 

1904  .     .     . 

1905  .     .     . 

1906  .     .     . 

1907  .     .     . 

1908  .     .     . 

1909  .     .     . 

1,369,276 
1,369,276 
1,642,930 
1,528,735 
4,014,631 
4,284,561 

16.00 
16.00 
18.90 
31.40 
18.10 
18.60 

.39 
.39 
.40 
.36 

.48 
.48 

8,544,339 
8,544,339 
12,436,557 
17,142,081 
35,409,961 
38,449,866 

6.24 

6.24 

7.56 

11.21 

8.82 
8.97 

Average 

20.60 

.42 

1      8.56 

1  Includes  $828,131  worth  of  fodder. 

2  Includes  $151,911  worth  of  fodder. 


308 


CORN  CROPS 


provement  of  varieties  they  are  destined  to  become  an 
important  crop  west  of  the  98th  meridian.  The  compara- 
tive acreage  and  value  of  non-saccharine  sorghums  com- 
pared with  corn  in  Kansas  and  Oklahoma,  as  compiled  in 
Bulletin  203,  Bureau  of  Plant  Industry,  United  States 
Department  of  Agriculture,  is  given  above. 

236.   Classification  of  non-saccharine  sorghums.  — 

Pith  juicy : 

(Very  juicy,  sweet  =  Sorgo.) 

Juice  scanty,  subacid  or  somewhat  sweet  or  dry  in 
certain  varieties. 

(1)  Heads  erect,  cylindrical,  spikelets  oval,  small, 
3-4  mm.  wide. 

Kafir    J  (a)  Seeds  white  : 

Group    ]  Glumes  greenish  white,  some  darker. 

I.  White  Kafir. 
Glumes  black  or  nearly. 

II.  BlackhuU  Kafir. 
(b)  Seeds  red : 

Glumes  deep  red  to  black. 

III.  Red  Kafir. 

(2)  Heads  pendent  but  sometime  secret,  ovate ; 
spikelets  broadly  obovate,  large,  4,  5-6 
mm.  wide. 

(a)  Seeds  white : 

Glumes  greenish  white,  silky,  seeds  flat- 
tened, awned.  IV.  White  Durra. 

Glumes  black,  seeds  smaller,  less  flattened, 
rare.  V.  BlackhuU  Durra. 


Dqrra 
Group 


(6)  Seeds  yellowish  to  reddish  brown : 

Glumes  short,  wrinkled,  reddish  to  black, 

not     silky ;     seeds     yellowish     brown ; 

florets  awned.  VI.  Yellow  Milo. 

Glumes  as  long  as  seeds,  greenish  white, 

seeds  reddish  brown,  not  awned. 

VII.  Brown  Durra. 


THE  NON-SACCHARINE  SORGHUMS 


309 


Broom- 
corn 
Type 


Pith  dry : 

Head  loose,   10-28  inches  long;    spikelets  oval  or 
obovate,      small,     2.5-3.5     mm.     wide, 
lemmas  awned : 
Rachis  one-fifth  as  long  as  branches. 

(a)  Branches  drooping,  seeds  reddish.  XI. 
Broom-corn.  Rachis  more  than  two- 
thirds  as  long  as  head  : 
(h)  Branches  of  panicle  drooping;  glumes  at 
maturity  spreading  and  involute  ;  seeds 
white  to  buff  (several  varieties).   . 

VIII.  Shallu. 
(c)  Branches  spreading  but  not  drooping, 
glumes  at  maturity  appressed,  not  in- 
volute;  seeds  white,  brown,  or  red. 
(Several  varieties,  corresponding  to  the 
red,  white,  and  blackhuU  varieties  of 
Kafir  and  Durra.  Also  standard  and 
dwarf.)  IX.  Kowliang. 

Head  compact,  erect  or  pendent,  spikelets  oval  or 
obovate,  small,  lemmas  awned : 
Rachis  two-thirds  as  long  as  head.    X.  Kowliang. 

237.  Kafir.  —  The  three  principal  varieties  of  kafir  are 
red,  white,  and  blackhull.  The  heads  are  erect,  in  con- 
trast to  the  durra  group,  in  which  the  heads  are  mostly 
recurved,  or  "  goosenecked."  The  white  and  blackhull 
varieties  both  grow  about  5  to  6  feet  high,  while  the  red 
is  8  to  12  inches  taller.  The  white  and  red  varieties  were 
first  introduced.  The  white  variety,  however,  was  not 
satisfactory  because  of  its  not  maturing  well,  and  the 
head  was  not  always  exerted  from  the  leaf  sheath,  thus 
inducing  rot  in  damp  weather.  The  red  variety  matured 
properly  and  soon  became  more  popular. 

The  objection  to  Red  Kafir  was  the  astringent  taste  of 
the  seed  coat,  common  to  all  kafirs  with  a  colored  seed 
coat.     The  blackhull,  a  white-seeded  variety,  appears  to 


310 


CORN  CROPS 


be  a  later  introduction,  having  attracted  attention  about 
1896.  It  had  all  the  good  qualities  of  Red  Kafir,  and  in 
addition    the    seed    was    not    astringent.     This    variety 

probably  furnishes  nine- 
tenths  of  the  kafir  crop 
to-day,  and  Red  Kafir  the 
other  tenth. 

238.  Durra. — The  char- 
acteristics of  this  group  are 
that  the  heads  are  mostly 
"  goosenecked  "  and  the 
seeds  are  large  and  flat. 
The  extensive  culture  of 
non-saccharine  sorghums 
in  this  country  began  with 
the  introduction  of  Brown 
Durra  and  White  Durra 
into  California  in  1874, 
but  the  culture  did  not 
become  general  in  the 
Great  Plains  region  until 
about  1890. 

The  White  Durra  is  com- 
monly known  as  "  Jerusa- 
lem corn,"  and  sometimes 
as  "  Egyptian  rice  corn." 
The  Brown  Durra  is  often 
called  "  Egyptian  corn." 
White  Durra  is  little 
grown,  as  it  is  frequently  injured  by  insects  and  diseases. 
The  grain  also  shatters  badly. 

Brown  Durra   has  continued   in  cultivation  especially 
in  southern  California  and  Texas.     The  total  area  of  White 


Fig.  106.  —  Plant  of  Blackhull  Kafir. 


THE  NON-SACCHARINE  SORGHUMS 


311 


and  Brown  Durras  was  estimated  at  50,000  to  60,000  acres 
in  1908.1 

239.  Milo,  or  Yellow  Milo,  was  introduced  about  1885, 
ten  years  later  than  the 
White  and  Brown  Dur- 
ras, but  it  quickly  be- 
came the  most  popular 
of  the  group,  the  area 
in  1908  being  estimated 
at  300.000  acres.  This 
variety  will  mature  in 
90  to  100  days  and  is 
adapted  to  culture  as 
far  north  as  south- 
western Nebraska.  In 
addition  to  the  standard 
varieties,  there  is  now 
a  dwarf  variety  well 
suited  to  cultivation  for 
grain  production. 

Compared  with  kafir, 
the  durras  are  better 
adapted  as  grain  pro- 
ducers but  not  so  well 
suited  for  forage  pro- 
duction. Milo  is  the 
best  suited  of  all  the 
sorghums  for  grain  pro- 
duction. Early  varie- 
ties of  milo  have  been 
developed  by  selection, 

which    adapts    it    to    a  Fig.  107.  — White  Kafir  Com. 

1  U.  S.  Dept.  Agr.,  Bur.  Plant  Indus.,  Bui.  175,  p.  34. 


312 


CORN  CROPS 


^■^'' 


,-">«■,., 


Fig.  108.  — Upright  Milo  head. 


Fig.     109.  — Pendent    form     of 
Milo  head. 


THE  NON-SACCHABINE  SORGHUMS 


313 


wide  range  of  conditions,  and  this  plant,  together  with 
Blackhull  Kafir,  is  the  best  of  the  sorghums  for  grain 
production. 

The  milos,  being  about  three  weeks  earlier  in  maturing 
than  the  kafirs,  have 
two  distinct  advan- 
tages :  in  Oklahoma 
and  Texas  they  can 
be  planted  early  and 
will  more  nearly  ma- 
ture before  the  severe 
midsummer  drought ; 
also,  they  may  be 
grown  farther  north 
and  at  higher  alti- 
tudes. 

240.  Shallu.— This 
plant  is  of  recent  in- 
troduction.  The 
stalks  are  tall  and 
slender,  with  large 
loose  and  open  pani- 
cles, approaching 
broom-corn  in  type. 
The  plant  comes  from 
India,  where  it  is  cul- 
tivated as  a  winter 
crop,  being  sown  in 
October  and  har- 
vested in  March.  It 
is  grown  for  both  seed 
and  forage.     Seed  of 

this    was    introduced  Fig.  no. —Yellow  Milo. 


314  CORN   CROPS 

and  tested  by  the  Louisiana  Agricultural  Experiment 
Station  about  twenty  years  ago.  It  is  occasionally 
grown  from  Kansas  to  Texas.  It  has  acquired  several 
local  names,  as  California  wheat,  Egyptian  wheat,  and 
Mexican  wheat. 

241.  Kowliang.  —  In  both  India  and  China  the  sorghums 
are  commonly  classed  with  millets.  "  Kowliang,"  or 
"  tall  millet,"  is  a  Chinese  name  given  to  distinguish  this 
variety  from  the  common  smaller  millets  (Panicum  and 
Chsetochloa) .  The  three  colors  of  seed  and  glume  found 
in  kafirs  and  durras  are  found  also  in  this  group,  namely, 
brown  seeds  with  black  glumes,  white  seeds  with  black 
glumes,  and  white  seeds  with  white  glumes.  There  are 
varieties  of  both  dwarf  and  standard  size,  4  to  11  feet  high. 

Kowliang  comes  from  northeast  China  and  the  adjacent 
territory  of  Manchuria,  38°  to  42°  north  latitude  —  the 
farthest  north  of  any  region  where  sorghums  have  been 
an  important  crop  for  any  great  length  of  time.  They 
are  extensively  cultivated  in  this  region  for  grain  and 
forage  and  the  stems  are  used  for  fuel. 

All  varieties  are  early-maturing,  and,  being  already 
adapted  to  a  region  farther  north  than  any  other  group 
of  sorghums  except  the  Early  Amber  varieties  (the  original 
Amber  type  also  came  from  China) ,  they  should  be  adapted 
to  a  similar  latitude  in  the  United  States.  They  have  not 
been  extensively  tried  in  this  country,  but  the  early  dwarf 
stocks  give  promise  of  furnishing  a  good  foundation  stock 
for  the  development  of  grain  sorghums  in  the  northern 
half  of  the  Great  Plains.  They  could  not  replace  Early 
Amber  sorghums  as  a  forage  crop. 


CHAPTER  XXVI 
CULTURAL  METHODS  FOR  SORGHUMS 

242.  Sorghums  are  grown  for  four  distinct  purposes : 
(a)  as  a  grain  crop  primarily,  (6)  as  a  forage  crop,  (c)  for 
sirup  manufacture,  and  (d)  for  broom-corn  brush. 

The  land  to  be  chosen  would  be  similar  in  each  case, 
but  the  principal  difference  in  cultural  methods  would 
come  in  method  of  sowing  and  harvesting. 

Because  the  sorghums  will  grow  on  poorer  and  drier 
land  than  any  other  of  our  cereals  is  to  be  taken  as  an 
indication  not  that  they  naturally  prefer  such  conditions, 
but  rather  that  they  are  capable  of  withstanding  greater 
hardships  than  other  crops.  Consequently^,  the  culture 
of  sorghums  may  extend  beyond  the  hmits  of  common 
cereals ;  but,  on  the  other  hand,  they  will  respond  as 
readily  to  manuring  and  to  favorable  environment  as 
will  any  plant,  on  good,  rich  land  producing  six  to  seven 
tons  of  cured  forage  per  acre. 

Preparation.  — •  The  land  is  prepared  much  as  for  corUo 
The  plowing  may  be  done  in  the  fall  or  in  the  spring. 
As  planting  does  not  take  place  until  rather  late  —  two 
to  four  weeks  after  corn,  —  there  is  ample  time  for  spring 
preparation  of  the  soil. 

GROWING  SORGHUMS  FOR  GRAIN 

243.  Varieties.— Blackhull  Kafir,  Milo,  Red  Kafir,  and 
Brown  Durra,  in  the  order  named,  are  the  principal  sor- 
ghums grown  for  grain. 

315 


316 


CORN   CROPS 


Fig.  111.  —  Heads  of  Sudan  Durra,  from  San  Antonio,  Tex.  On  left,  in 
flower  latter  part  of  May,  not  injured  by  midge.  On  right,  in  flower 
September  1,  and  almost  sterile,  due  to  midge. 


CULTURAL  METHODS  FOR   SORGHUMS  317 

244.  Time  of  Planting.  —  Grain  sorghums  are  usually 
planted  soon  after  corn;  the  time  ranging  from  March 
to  June  in  the  Southern  States,  while  as  far  north  as 
Nebraska  the  planting  must  be  as  early  as  possible  in 
order  to  insure  maturing.  Planting  in  Nebraska  practi- 
cally coincides  with  corn  planting,  about  May  10. 

In  the  San  Antonio  region  of  Texas  it  has  been  found 
necessary  to  plant  very  early  in  order  to  avoid  the  sorghum 
midge,  an  insect  that  becomes  very  numerous  in  June 
and  practically  prevents  all  seeding  from  that  date  on. 
In  order  to  avoid  the  midge,  planting  must  be  early. 
According  to  one  experiment  reported  in  1911,  eleven  va- 
rieties of  grain  sorghums  planted  on  March  4  yielded  23.1 
bushels,  while  early  varieties  planted  on  March  15  gave 
only  profitable  yields,  and  no  varieties  planted  on  April  1 
were  profitable.^ 

245.  Rate  of  planting.  —  Grain  sorghums  are  usually 
planted  in  rows  3  or  SJ  feet  apart ;  the  plants  6  to  8  inches 
apart  for  the  milos  and  durras,  and  8  to  10  inches  for 
kafirs.  On  very  fertile  soils  the  planting  should  be 
thicker  than  this.  The  amount  of  seed  required  will  be 
3  to  5  pounds  per  acre.  With  durras  a  higher  percentage 
of  the  heads  "  gooseneck,"  or  recurve,  when  planted  thin 
than  when  planted  thick. 

246.  Methods  of  planting.  —  Corn-planting  machinery 
is  generally  used  for  sorghums,  the  only  change  necessary 
being  to  use  special  plates  for  dropping  or  to  adapt  the 
corn-dropping  plates.  The  corn-planting  plates  can  be 
adapted  by  filling  the  holes  with  lead  and  boring  out  to 
the  right  size.     Grain  sorghums  are  always  drilled. 

Listing  is  a  method  common  in  regions  of  low  rainfall, 

1  Grain  Sorghum  Production  in  the  San  Antonio  Region  of  Texas. 
U.  S.  Dept.  Agr.,  Bur.  Plant  Indus.,  Bui.  237.     1912. 


318 


CORN   CROPS 


but  in  regions  of  higher  rainfall  and  heavy  soils  surface 
planting  is  better.  When  planted  in  a  lister  furrow  the 
seed  should  not  be  covered  deeper  than  is  necessary  to 


Fig.  112.  —  Plat  of  Milo  selected  for  erect  heads. 

insure  good  germination,  as  it  rots  very  easily  when  planted 
deep  or  when  the  soil  is  cold  or  wet. 

Surface  planting  is  ordinarily  done  with  the  two-row 
corn-planter ;  the  grain  drill  is  sometimes  employed,  how- 
ever, by  using  only  every  fourth  or  fifth  hole. 

247.  Tillage. — The  same  tools  are  used  in  general  for 
cultivating  sorghum  as  for  corn,  and  in  much  the  same 
manner.  However,  sorghum,  especially  when  listed,  is 
much  slower  in  growth  than  corn  for  the  first  four  weeks, 


CULTURAL   METHODS  FOB   SORGHUMS  319 

and  consequently  more  skill  is  required  to  clean  out  the 
weeds.  Young  sorghum  is  tougher  and  less  likely  to  break 
than  is  j^oung  corn,  which  is  an  advantage,  since  it  permits 
of  the  use  of  such  tools  as  harrows  and  weeders  oftener  and 
longer  than  is  the  case  with  corn.  With  surface-planted 
sorghums,  by  the  proper  use  of  harrows  and  weeder  it  is 
often  not  necessary  to  give  more  than  one  thorough 
cultivation  with  the  shovel  cultivator. 

With  listed  sorgum,  the  harrow  and  lister  cultivators 
should  be  used  for  the  first  cultivation.     When  the  plants 


Fig.  113.  —  Field  of  White  Kafir  in  shock. 

are  8  to  10  inches  high  a  very  thorough  cultivation  should 
be  made  with  the  cultivator,  to  be  followed  later  by  such 
shallow  cultivation  as  is  necessary  to  keep  down  weeds. 

248.  Cutting.  —  When  grown  for  grain  the  heads  should 
be  fully  ripe.  If  cut  for  silage,  the  seeds  should  be  in  the 
soft  dough  stage,  as  the  ripe  seeds  in  silage  are  very  likely 
to  pass  through  the  animal  without  digestion. 

The  corn-binder  is  the  best  and  most  economical 
implement  for  harvesting  on  a  large  scale.  With  smaller 
areas  the  sled  cutter  is  used,  or  the  crop  is  cut  by  hand. 


320  CORN  CROPS 

Various  plans  for  harvesting  only  the  heads  have  been 
tried,  but  all  these  have  proved  less  satisfactory  than 
harvesting  the  whole  plant. 

249.  Curing.  —  The  grain  sorghum,  however  harvested, 
should  be  set  up  in  shocks  until  well  cured.  Precaution 
should  be  taken  to  set  the  base  of  the  shock  wide  and  to 
tie  well  about  the  heads.  The  heads  being  heavy,  the 
shocks  are  very  likely  to  fall  over. 

Before  threshing,  the  sorghum  heads  should  be  very 
dry,  as  the  grain  heats  and  spoils  quickly  when  stored  if 
at  all  damp.  This  will  require  four  to  six  weeks  in  the 
shock. 

250.  Hauling  and  storing.  —  Where  the  fodder  is  fed, 
it  is  very  common  to  haul  from  the  field  as  used.  Sorghum 
will  remain  in  very  good  condition  for  several  months 
when  bound  and  set  in  large  shocks.  If  not  to  be  used  for 
three  months,  it  is  usually  better  to  haul  and  stack. 

Baling  is  sometimes  practiced,  a  hop  or  broom-corn 
baler  being  used  as  the  bundles  are  not  broken  apart. 

When  the  stover  and  grain  are  to  be  fed  separately  the 
bundles  are  sometimes  beheaded  with  a  broadax  or  heavy 
knife.  The  heads  are  then  stored  in  a  dry  place,  to  be 
fed  whole  or  to  be  threshed. 

251.  Threshing. — The  whole  bundles  are  sometimes 
run  through  an  ordinary  grain-thresher,  or  only  the  heads 
run  in  and  the  bundles  then  withdrawn.  The  labor  is 
heavy  in  both  cases  and  it  is  often  considered  better  to 
behead  the  bundles  and  thresh  only  the  heads. 

Yields 

252.  As  shown  by  the  table  on  page  306,  the  average 
yield  of  grain  sorghums  in  Kansas  and  Oklahoma  is  not 
equal  to  that  of  Indian  corn ;  but  in  these  States  corn  is 


CULTURAL  METHODS  FOR   SORGHUMS  321 

raised  in  the  part  of  the  State  having  heaviest  rainfall, 
and  sorghum  in  the  drier  part. 

West  of  the  25-inch-rainfall  line,  grain  sorghums  will 
equal  or  outyield  corn.  The  advantage  increases  as  rain 
decreases.  Yields  of  twelve  to  twenty  bushels  of  grain 
sorghum  are  often  harvested  when  corn  is  a  failure  from 
drought.  Twenty  bushels  per  acre  is  considered  an  aver- 
age crop  and  forty  bushels  per  acre  a  good  crop.  Yields 
of  sevent}^  bushels  have  been  known. 

GROWING   SORGHUMS    FOR   FORAGE 

253.  Sweet  sorghums  are  used  more  extensively  when 
grown  primarily  for  forage  than  are  the  non-saccharine. 

Since  the  foliage  of  all  sorghums  remains  green  until 
the  heads  are  mature,  a  fair  quality  of  coarse  forage  is 
secured  when  sorghums  are  grown  for  grain.  About  one- 
half  the  sorghum  crop  is  sown  primarily  for  fodder,  to  be 
cut  before  heads  are  ripe  and  cured  as  fodder  or  hay.     " 

254.  Time  of  planting.  —  In  the  Gulf  States  sorghum 
is  often  sown  early  so  that  the  crop  may  be  cut  two  or 
three  times,  though  sowing  may  continue  for  several 
months.  In  the  Central  States  sowing  is  usually  after 
corn  planting,  generally  in  the  month  of  June. 

255.  Rate  of  planting.  —  Sorghum  for  forage  is  either 
sown  thick  in  drill  rows  about  3  feet  apart  and  cultivated, 
or  sown  close,  either  broadcast  or  with  the  grain  drill. 

When  sown  in  rows  to  be  cultivated,  the  methods  are 
similar  to  those  for  growing  grain  except  that  about  15 
pounds  of  seed  per  acre  is  used  instead  of  2  to  5  pounds. 

When  sown  broadcast,  one  to  two  bushels  per  acre  of 
seed  are  used ;  the  thinner  sowing  is  done  on  poorer  land 
or  in  a  dry  climate,  and  the  thicker  seeding  under  the  most 
favorable  conditions. 


322 


CORN  CROPS 


256.  Methods  of  planting.  —  Which  of  the  two  methods 
shall  be  employed  —  drilling  or  broadcasting  —  depends 
on  circumstances.  In  regions  of  low  rainfall,  drilling  in 
wide  rows  and  cultivating  is  the  surer  method,  but  in 
more  humid  regions  there  is  little  difference  in  yield. 
On  the  other  hand,  drilling  in  rows  increases  the  cost 
because  of  the  amount  of  cultivation  necessary.  The 
fodder  is  also  coarser. 

Harvesting  forage  sorghum 

257.  When  cultivated  in  rows  the  best  method  of 
harvesting  is  with  a  corn-binder.  The  bundles  are  set  up 
in  small  shocks  to  cure.  In  four  to  six  weeks  several 
small  shocks  may  be  set  together  in  large  shocks,  which 


Fig.  114.  —  Cutting  sorghum  forage  with  a  mower. 


CULTURAL   METHODS   FOR   SORGHUMS  323 

are  securely  tied  near  the  top  and  left  in  the  field  to  be 
hauled  as  used.  A  better  method  is  to  stack  in  large 
stacks,  but  care  must  be  observed  that  the  fodder  is  well 
cured  before  stacking. 

When  sown  broadcast  the  crop  is  usually  cut  with  a 
mower  and  handled  as  coarse  hay,  or  cut  with  the  grain- 
binder. 

When  cut  with  a  mower  a  stubble  of  6  inches  should  be 
left.  This  tall  stubble  facilitates  drying,  and  also  gath- 
ering the  heavy  fodder  with  a  hayrake.  Heavy  sorghum 
hay  dries  very  slowly  and  should  be  left  for  one  to  two 
weeks  in  the  swath  before  raking  and  cocking.  It  should 
be  thoroughly  cured  in  the  cocks  before  stacking. 

258.  An  average  yield  of  cured  fodder  varies  from  3  to 
6  tons  per  acre.  Very  heavy  yields  of  10  tons  per  acre 
have  been  reported  from  one  cutting.  Where  sorghum 
is  cut  two  or  three  times  a  season,  as  in  the  South,  the 
relative  yield  of  the  different  cuttings  depends  on  the 
method  of  handling.  If  the  first  cutting  is  allowed  to 
become  quite  ripe,  the  following  cutting  will  be  light; 
but  if  the  first  crop  is  cut  quite  green,  the  second  cutting 
may  be  as  heavy  as,  or  heavier  than,  the  first. 

259.  Seed  crop.  —  Twenty-five  to  thirty  bushels  of 
seed  per  acre  is  considered  an  average  yield.  All  sorghum 
sown  in  rows  for  fodder  or  planted  thin  for  sirup-making 
produces  a  good  crop  of  seed.  Most  of  the  commercial 
seed  of  sweet  sorghums  comes  from  this  source. 


CHAPTER  XXVII 
UTILIZING   THE  SORGHUM  CROP 

260.  In  Asia  and  Africa  the  grain  of  sorghum  is  utiHzed 
principally  as  human  food,  in  the  United  States  as  stock 
food. 

The  seed  coat  is  hard  and  rather  indigestible,  therefore 
all  sorghum  grain  fed  to  live  stock  should  be  ground. 

Composition.  —  The  composition  of  kafir  is  shown  by 
the  following  summary  :  ^  — 

Food  Constituents  in  Kafir.     In  Fresh  or  Air-dry 
Material 


PllO- 

Nitro- 

Water 

Ash 

TEIN 

Fiber 

gen-free 
Extract 

Fat 

Authority 

Per 

Per 

Per 

Per 

Per 

Cent 

Cent 

Cent 

Cent 

Per  Cent 

Cent 

Kafir          (whole 

plant  green)    . 

76.13 

1.75 

3.22 

6.16 

11.96 

0.78 

Penn.     Station 

Kafir          (whole 

plant  green)    . 

76.05 

1.44 

2.34 

8.36 

11.41 

0.40 

N.  Y.  (Cornell) 
Station 

Average 

76.09 

1.60 

2.78 

7.26 

11.69 

0.59 

Kafir          fodder 

(whole  plant   . 

10.94 

5.48 

3.31 

30.37 

47.40 

2.50 

N.C.      Station 

Kafir          fodder 

(without 

heads)    .     .     . 

8.67 

7.14 

4.89 

28.02 

49.75 

1.53 

Kans.    Station 

Kafir        (mature 

head)      .     .     . 

16.23 

2.02 

6.92 

6.79 

65.18 

2.86 

N.C.      Station 

Kafir  seed      .     , 

9.31 

1.53 

9.92 

1.35 

74.92 

2.97 

Kans.    Station 

Kafir  flower   .     . 

16.75 

2.18 

6.62 

1.16 

69.47 

3.82 

N.C.     Station 

Cycl.  of  Agr.  IV  :  387. 
324 


UTILIZING    THE  SORGHUM  CROP  325 

Kafir  and  other  sorghum  seeds  are  considered  to  be 
very  starchy  foods.  For  good  results  they  require  that 
some  protein  food,  as  alfalfa  hay  or  cottonseed  meal,  be 
fed  with  them.  Ten  per  cent  cottonseed  meal  is  sufficient. 
Kafir  grain  fed  alone  is  also  constipating,  and  this  tend- 
ency is  corrected  by  the  addition  of  a  protein  food  fed 
in  connection. 

When  fed  to  cattle,  horses,  and  sheep,  good  results  are 
secured,  though  pound-for-pound  feeding  experiments 
show  sorghum  to  be  not  quite  so  valuable  as  corn.  In 
general,  for  fat  stock,  80  to  90  pounds  of  corn  have  been 
found  to  equal  100  pounds  of  kafir  or  milo  when  fed  in 
comparison. 

261.  Poultry  food.  —  Sorghum  seed  is  one  of  the  best 
poultry  foods  and  enters  into  a  large  proportion  of  these 
foods  found  on  the  market.  It  is  considered  superior  to 
corn.  For  poultry  the  seed  need  not  be  ground  but  is  fed 
whole,  either  threshed  or  in  the  head. 

262.  Soiling  or  green  feed.  —  Sorghum  is  probably  the 
most  popular  crop  to  cut  and  feed  green.  The  sweet 
sorghums  are  used  principally  for  this  purpose.  The 
superiority  of  sorghum  for  this  use  lies  in  its  large  yield, 
its  sprouting  up  from  the  roots  so  that  the  crop  may  be 
cut  several  times  in  succession,  and  its  drought  resistance. 
Sorghum  will  remain  green  and  growing  under  drier 
conditions  than  will  other  forage  crops,  furnishing  succu- 
lent food  at  the  time  it  is  most  needed. 

For  green  feeding  it  is  usually  drilled  very  thick,  in 
rows  3  feet  apart. 

An  acre  of  green  sorghum  producing  12  tons  will  feed 
twenty  head  of  stock  for  twenty  days,  allowing  60  pounds 
per  head  each  day. 

263.  Pasture.  —  Sorghum    is   used    considerably   as   a 


326  CORN   CROPS 

pasture  crop.  For  this  purpose  it  is  sown  rather  thick, 
2  to  3  bushels  per  acre.  Stock  is  turned  in  when  the  crop 
is  3  to  4  feet  high. 

For  pasturing,  the  field  should  be  divided  into  lots  and 
enough  stock  should  be  turned  in  to  eat  down  the  crop 
in  about  two  weeks.  The  stock  should  then  be  removed 
to  another  lot  and  the  pasture  given  four  to  six  weeks  to 
grow  up  again.     This  would  require  three  to  four  lots. 

It  is  estimated  that  one  acre  will  furnish  grazing  for 
the  equivalent  of  one  animal  for  one  hundred  days,  or 
ten  animals  for  ten  days. 

264.  Sorghum  mixtures  for  pasture.  —  For  pasture 
purposes  German  millet  is  sometimes  mixed  with  sorghum 
and  gives  good  results.  Cereals  have  been  used  as  a 
mixture,  but  it  is  doubtful  whether  they  add  to  the  value 
as  pasture.  In  the  South,  it  has  been  recommended  to 
mix  sorghum  and  cowpeas,  for  both  forage  and  pasture. 
Cowpeas  give  a  better-balanced  ration.  For  pasture 
the  sorghum  and  cowpeas  should  be  drilled  in  rows  about 
8  to  12  inches  apart,  in  alternating  rows. 

265.  Sorghum  for  silage.  —  Within  the  corn-belt,  sor- 
ghum compares  favorably  with  corn  as  a  silage  crop. 
In  regions  of  less  than  25  inches  rainfall,  sorghum  will 
probably  come  to  be  the  most  important  silage  crop. 
In  the  South,  also,  it  is  likely  to  supersede  corn  for  silage, 
especially  where  the  crop  is  to  be  grown  on  rather  poor 
land. 

Sorghum  silage  is  more  difficult  to  preserve  than  corn, 
being  more  likelj^  to  ferment.  When  well  preserved  it 
appears  to  have  a  feeding  value  about  equal  to  that  of 
corn  silage,  though  very  little  experimental  work  on 
this  point  has  been  done.  Sorghum  for  silage  is  now  in 
extensive  use  in  many  places  in  the  Southern  States, 


UTILIZING   THE   SOBGHUM  CROP  327 

266.  Sorghum  poisoning.  —  Sorghum  pasture  under 
some  conditions  is  a  virulent  poison.  This  is  due  to 
prussic  acid  forming  in  the  leaves  under  certain  condi- 
tions. The  conditions  favoring  the  development  of  prussic 
acid  seem  to  be  hot,  clear,  and  dry  weather,  producing 
a  stunted  growth.  Poisoning  is  most  common  in  semiarid 
regions.  When  conditions  are  right  for  developing  poison, 
the  sorghum  should  be  pastured  with  caution,  as  the  poison 
acts  quickly  and  there  is  no  known  remedy.  Cattle 
should  not  be  pastured  on  stunted  or  drought-stricken 
sorghum.  Where  it  is  desired  to  test  the  pasture,  prob- 
ably the  best  way  is  to  allow  only  a  single  animal  to  graze 
the  field  for  a  day  or  two. 

When  poisonous  sorghum  is  cut  and  allowed  to  lie 
until  wilted,  the  poisonous  property  entirely  disappears. 


CHAPTER  XXVIII 
SORGHUM  FOR  SIRUP-MAKING 

As  discussed  heretofore  (see  page  296),  sorghum  has 
had  an  extensive  use  in  the  United  States  for  sirup 
manufacture.  The  process  of  sirup-making  is  so  simple 
that  nothing  more  is  necessary  than  a  roller  press  for 
extracting  the  juice,  and  a  single  evaporating  pan.  In  a 
few  cases  rather  extensive  plants  have  been  established, 
but  most  of  the  sirup  has  been  made  in  small  local  plants. 

267.  For  sirup  the  sweet  sorghums  are  used,  as  Amber, 
Orange,  Sumac,  and  Gooseneck.  There  are  strains  of  all 
these  varieties  selected  for  sirup-making.  (See  descrip- 
tion of  these  varieties,  pages  297-300.) 

268.  For  sirup  the  sorghum  is  planted  and  cultivated 
practically  as  described  for  the  culture  of  grain  sorghums. 

269.  Time  of  harvesting.  —  The  sugar  content  of  sor- 
ghum at  different  stages  of  growth  as  determined  by  Collier, 
the  result  of  2740  analyses,  is  given  as  follows  :  ^  — 

Sugar  Content  of  Sorghum  at  Different  Stages  of  Growth 


Stage  of  Cutting 

Sucrose 

Invert  Sugar 

Panicles  just  appearing 
Panicles  entirely  out    . 
Flowers  all  out  . 

Per  Cent 

1.76 
3.51 
5.13 

7.38 

8.95 

10.66 

11.69 

Per  Cent 

4.29 
4.50 
4.15 

Seed  in  milk 

3  86 

Doughy,  becoming  dry 
Dry,  easily  split      .     . 
Hard 

3.19 
2.35 
1.81 

1  Sorghum    Sirup    Manufacture.     U.    S.   Dept.   Agr.,   Farmers'   Bui. 
.^77;  12. 

328 


SORGHUM  FOR   SIRUP-MAKING  329 

270.  Sorghum  increases  not  only  in  total  weight  until 
mature,  but  also  in  the  percentage  of  sugar.  The  seed 
should  reach  a  hard  dough  stage  before  cutting. 

Stripping.  —  For  best  results  the  leaves  should  be 
stripped.  This  is  done  while  the  canes  are  standing.  The 
canes  are  often  pressed  without  removing  the  leaves,  but 
if  this  is  the  case,  the  yield  of  juice  is  less  and  the  im- 
purities are  much  greater. 

Cutting.  —  The  canes  are  cut  by  hand  or  with  a  corn- 
binder.  In  hot  weather,  cutting  should  be  done  not 
more  than  two  days  before  grinding,  as  there  is  danger  of 
fermentation  developing.  In  cool  fall  weather,  however, 
canes  are  often  kept  in  large  shocks  for  one  to  two  weeks 
after  cutting. 

When  a  heavy  frost  occurs  the  sorghum  should  be  cut 
and  placed  in  large  shocks  at  once.  If  it  is  to  stand  for 
some  time,  both  leaves  and  heads  should  be  left  on.  In 
large  shocks,  with  cool  weather  the  sorghum  may  be  kept 
with  little  loss  for  three  or  four  weeks. 

A  heavy  freeze  will  do  no  harm  provided  the  cane  can 
be  ground  at  once  upon  thawing ;  but  after  thawing  it  is 
likely  to  go  out  of  condition  in  a  very  short  time. 

271.  An  average  yield  of  green  sorghum  would  be  8  to 
10  tons,  though  it  may  vary  from  5  to  15  tons. 

The  yield  of  sirup  depends  on  the  kind  of  mill,  quahty 
of  the  sorghum,  and  quahty  of  the  juice. 

A  poor  mill  may  extract  only  30  per  cent  of  the  total 
juice,  while  with  a  good  three-roller  mill  60  per  cent  of  the 
original  weight  may  be  extracted  as  juice,  or  1200  pounds 
to  a  ton  of  canes. 

Juice  varies  in  quality,  containing  8  to  15  per  cent  of 
sugar.  The  juice  is  concentrated  by  boiling  until  it  con- 
tains about  70  per  cent  of  solid  matter  and  30  per  cent  of 


330  CORN  CROPS 

water.     The  amount  of  sirup  produced  from  a  ton  of 
canes  is  therefore  very  variable. 

In  general,  a  ton  of  canes  will  give  700  to  1200  pounds 
of  juice,  which  in  turn  will  yield  10  to  30  gallons  of  sirup, 
according  to  quality. 

272.  The  manufacture  of  sorghum  sirup  consists  of  three 
steps:  (1)  extraction  of  juice;  (2)  clarification  of  the  raw 
juice;    (3)  evaporation  of  juice. 

The  extraction  is  done  with  heavy  roller  presses  of  either 
the  two-roller  or  three-roller  type.  The  juice  is  then' 
run  into  settling  tanks,  where  impurities  in  suspension 
are  allowed  to  settle  out. 

The  clarification  is  accomplished  in  some  cases  by 
merely  allowing  the  raw  juice  to  settle  for  some  time. 
Settling  is  hastened  by  heating.  Sometimes  fine  yellow 
clay  is  added,  which  aids  in  settling.  When  the  juice  is 
somewhat  acid,  lime  also  is  added  to  the  heated  juice. 
After  clarification  the  clear  juice  is  drawn  off  to  be  con- 
centrated. 

Concentration  takes  place  in  large,  shallow  pans,  where 
the  juice  is  kept  boiling  by  a  well-regulated  fire.  Ordi- 
narily the  pan  is  divided  into  compartments,  the  boihng 
juice  flowing  slowly  in  a  thin  layer  from  one  end  to  the 
other.  By  the  time  the  outflow  is  reached,  the  juice 
should  be  concentrated  into  sirup.  In  very  small  plants 
the  juice  is  merely  boiled  down  in  kettles. 


CHAPTER  XXIX 

BROOM-CORN 

Broom-corn  belongs  to  the  non-saccharine  sorghums, 
resembhng  Shallu  or  KowUang  more  than  others.  It  is 
characterized  by  very  short  rachis  and  long,  slender, 
seed-bearing  branches.  The  plant  is  grown  principally 
for  the  seed  head,  or  ''  brush,"  having  practically  no  forage 
value. 

273.  Historical.  —  The  origin  of  broom-corn  is  not 
known,  though  it  was  cultivated  and  used  for  making 
brooms  two  hundred  and  fifty  years  ago  ^  in  Italy,  where 
it  apparently  had  its  first  general  culture.  References  are 
made  to  its  culture  in  the  United  States  about  the  year 
1800.  The  following  statement  appears  regarding  it  in 
a  book  entitled  "  The  Pennsylvania  Farmer,"  published 
in  1804 : 2  '^  A  useful  plant,  the  cheapest  and  best  for 
making  brooms,  velvet  whisks,  etc.  The  grain  for  poultry, 
etc.,  a  few  hills  or  rows  of  it  in  the  garden  or  cornfield 
suffice  for  family  purposes." 

While  its  value  was  thus  recognized,  its  culture  did  not 
become  important  until  several  decades  later. 

274.  Statistics  of  culture.  —  During  the  past  forty 
years,  broom-corn  culture  has  developed  rapidly,  as  shown 
by  the  crop  harvested  for  the  past  three  census  years :  — 

Year  Pounds 

1879 29,480,106 

1889 38,557,429 

1899 90,947,370 

^  Mentioned  by  Casper  Bauhin  as  used  for  this  purpose  in  1658. 
2  Twelfth  Census.     Vol.  VI,  Part  II,  p.  519. 
331 


332 


CORN  CROPS 


The  crop  practically  trebled 
in  thirty  years. 

Broom-corn  culture  has 
always  been  concentrated  to 
certain  rather  limited  regions  : 
Four  States  in  1879  —  lUi- 
nois,  Kansas,  Missouri,  and 
New  York  —  produced  80  per 
cent  of  the  crop.  In  1889 
four  States,  the  first  three 
named  above  and  Nebraska, 
produced  89  per  cent  of  the 
crop.  In  1899  the  last-named 
four  States  and  Oklahoma 
produced  90  per  cent  of  the 
crop. 

In  1899  Illinois  alone,  which 
has  been  the  leading  State 
in  broom-corn  production  for 
forty  years,  produced  66.7 
per  cent  of  the  entire  crop 
in  the  United  States,  while 
50.1  per  cent  of  the  entire 
crop  was  grown  in  three 
counties. 

The  twenty-two  counties 
of  the  United  States  produc- 
ing more  than  1000  acres 
each  are  shown  in  the  fol- 
lowing table,  as  reported  by 
the  Twelfth  Census :  — 


115.  — Broom-corn,  sorghum,  and  hybrid  between  the  two  : 
a,  broom-corn ;  b,  hybrid  ;  c,  black-seeded  sorghum. 


BROOM-CORN 


333 


County 

State 

Acres 

Pounds 
Produced 

AVERAGH 

Yield 
PER  Acre 

Coles    .... 

Illinois 

34,597 

23,948,030 

692 

Douglas    . 

Illinois 

22,356 

14,768,780 

661 

Moultrie  . 

Illinois 

10,256 

6,815,530 

665 

Cumberland 

Illinois 

6,619 

2,738,710 

414 

Edgar 

Illinois 

6,248 

4,085,860 

654 

Woods 

Oklahoma 

6,086 

1,292,670 

212 

McPherson 

Kansas 

5,684 

2,890,330 

509 

Reno    .     . 

Kansas 

5,137 

1,691,090 

329 

Rice     .     . 

Kansas 

4,167 

1,366,030 

328 

Henry 

Missouri 

3,753 

1,177,950 

314 

Shelby      . 

Illinois 

3,246 

1,826,670 

563 

Clark  .     . 

Illinois 

2,446 

1,210,140 

495 

Henry 

Illinois 

2,000 

1,298,450 

649 

Allen   .     . 

Kansas 

1,952 

566,480 

290 

Cass     .     . 

Nebraska 

1,726 

776,580 

450 

Stafford    . 

Kansas 

1,684 

553,710 

329 

Jasper 

Ilhnois 

1,496 

651,560 

436 

Piatt    .     . 

Illinois 

1,454 

950,710 

654 

Sheridan 

Kansas 

1,307 

305,910 

234 

Cheyenne 

Kansas 

1,090 

252,940 

232 

Stevens    . 

Kansas 

1,054 

267,680 

254 

Polk     .     . 

Nebraska 

1,051 

498,000 

474 

275.  Varieties.  —  Seedsmen  list  broom-corn  under  at 
least  a  dozen  variety  names,  but  these  names  have  little 
significance.  There  are  two  types,  known  as  (1)  stand- 
ard, normally  growing  about  12  feet  high  with  a  brush 
18  to  28  inches  in  length,  and  (2)  dwarf  broom-corn, 
growing  4  to  6  feet  in  height  and  producing  a  brush  12  to 
18  inches  in  length. 

The  standard  type  is  used  for  the  manufacture  of  large 
brooms. 

While  dwarf  brush  is  also  used  to  some  extent  in  the 
manufacture  of  large  brooms,  the  straw  is  generally  too 


334  CORN   CROPS 

fine  and  weak  for  this  purpose.  The  dwarf  type,  however, 
is  almost  exclusively  used  in  whisk  brooms.  There  is 
some  variation  in  different  strains.  Very  often  the  large 
manufacturers  keep  on  hand  seed  of  the  strains  best  suited 
to  the  needs  of  the  trade,  and  are  ready  to  supply  growers 
with  this  seed. 

276.  Brush.  —  The  brush  should  be  bright  and  of  a 
uniform  light  green  color.  When  the  head  does  not  fully 
exsert  from  the  ''  boot,"  or  upper  leaf  sheath,  the  base  of 
the  brush  is  likely  to  take  on  a  red  color,  which  is  very 
undesirable.  The  discoloring  is  most  common  when  con- 
siderable rain  occurs  during  the  maturing  season.  This 
is  a  very  common  fault  of  the  dwarf  variety  and  necessi- 
tates breaking  over  the  brush  as  soon  as  it  is  well  grown 
so  that  it  will  hang  down.  For  this  reason  dwarf  broom- 
corn  is  more  successfully  grown  in  rather  dry  climates, 
most  of  it  at  present  being  cultivated  in  Kansas  and 
Oklahoma. 

Length  of  brush.  —  In  general,  the  longer  the  brush 
the  better,  all  other  qualities  being  equal.  There  is  some 
danger  that  verj-  long  brush  may  be  coarse.  Brush 
that  is  both  fine  and  long  is  the  most  valuable. 

Rachis.  —  The  rachis  should  be  short,  with  no  central 
*'  core  "  of  stiff  branches  extending  upward  in  the  center. 

Shape  of  head.  —  The  head  should  be  broom-shaped 
rather  than  conical,  with  all  branches  approximately  the 
same  length. 

Flexibility.  —  The  brush  should  be  flexible  and  tough. 
This  condition  is  attained  both  by  proper  climatic  condi- 
tions and  by  proper  harvesting. 

277.  Culture  of  broom-corn.  —  The  selection  and  prepa- 
ration of  land,  method  of  planting,  cultivating,  and  so  on, 
are  no  different  in  general  from  those  in  the  culture  of 


BROOM-CORN 


335 


other  sorghum  crops.  However,  quality  and  uniformity 
in  the  crop  is  as  important  as  yield,  and  more  precaution 
must  therefore  be  taken  to  have  the  land  uniform,  and  the 


Fig.  116.  —  Poor  and  good  heads  of  standard  and  dwarf  broom-corn  (after 
C.  P.  Hartley)  :  a,  poor  head  of  dwarf  with  large  center ;  h,  head  of 
dwarf  inclosed  in  "  boot "  ;  c,  good  grade  of  dwarf  for  whisks ;  d,  long 
head  of  dwarf  with  characteristic  weakness  at  point  x ;  e  and  /,  good 
grades  of  standard  hurl ;  g,  good  head  of  self-working ;  h,  poor  grade 
of  standard  because  of  heavy  center ;  i,  smutted  head. 

stand  uniform.  Also,  the  cost  of  harvesting  is  much 
increased  if  the  crop  does  not  ripen  so  that  it  can  all  be 
harvested  at  one  time. 


336  CORN   CROPS 

Land.  —  Any  productive  soil  will  raise  broom-corn. 
The  principal  consideration  is  that  the  soil  be  uniform. 
One  reason  why  the  culture  of  this  plant  has  been  so  suc- 
cessful in  central  Illinois  is  because  of  the  extensive  areas 
of  uniform  soil. 

Planting 

278.  Time  of  planting.  —  The  planting  of  broom-corn 
usually  begins  about  two  weeks  later  than  the  planting 
of  field  corn  and  may  be  continued  for  a  period  of  four 
weeks.  In  the  Central  States,  planting  is  done  from 
the  middle  of  May  to  the  end  of  June  and  harvesting  begins 
the  middle  of  August.  It  is  often  desirable  to  distribute 
the  planting  so  that  the  harvesting  will  not  come  too 
much  at  one  time. 

Method  of  planting.  —  The  width  of  row  varies  from 
3  feet  for  dwarf  varieties  to  3J  feet  for  standard  varie- 
ties. The  distance  apart  in  row  is  2  inches  in  dwarf 
and  3  inches  in  standard  varieties.  The  planting  should 
be  uniform,  as  the  brush  will  be  too  coarse  where  the  stalks 
are  thin,  and  undersized  where  the  planting  is  too  thick. 

Drilling  is  the  ordinary  method  of  planting.  The  ordi- 
nar}^  corn-planter,  with  special  plates  for  broom-corn  seed, 
is  satisfactory. 

Replanting  thin  places  is  not  practicable,  and  thinning 
the  stand  is  too  expensive.  It  is,  therefore,  very  impor- 
tant to  take  every  precaution  to  secure  a  perfect  stand  at 
the  beginning.  It  is  hardly  necessary  to  state  that  the 
land  should  be  clean  and  in  good  tilth,  and  the  seed  should 
be  carefully  cleaned  and  of  good  germinating  quality. 

279.  Tillage.  —  The  same  tools  and  methods  of  cultiva- 
tion that  are  successful  with  Indian  corn  are  effective  with 
broom-corn,  except  for  the  fact  that  broom-corn  is  more 


BROOM-COBN 


337 


delicate  and  grows  slowly  the  first  three  weeks,  necessitat- 
ing greater  care  and  skill. 

280.  Time  of  harvesting. — ^In  order  to  get  a  good  green 
color  and  tough,  flexible  brush,  the  corn  must  be  cut  quite 
green,  or  just  as  soon  as  the  brush  has  reached  full  growth. 
The  best  time  is  when  just  past  full  bloom. 

If  allowed  to  ripen,  the  brush  loses  color  and  becomes 
brittle,  and  the  selling  price  for  such  brush  is  often  less 


'^^^^^m 


Fig.  117.  — Standard  broom-corn,  tabled  and  ready  for  hauling. 

than  one-half  that  of  high-grade  stock.  On  the  other 
hand,  when  allowed  to  ripen,  10  to  20  bushels  of  seed  per 
acre  is  secured,  which  is  valuable  as  a  poultry  and  stock 
food.  It  is  generall}^  conceded  that  the  loss  in  value  to  the 
brush  is  much  greater  than  the  value  of  the  seed  crop, 
a,lthough  in  California  the  seed  crop  is  quite  generally 
harvested ;   but  this  is  not  customary  in  other  places. 

Cutting  the  brush.  —  Dwarf  broom-corn  is  usually 
"  pulled,"  while  the  standard  type  is  "  tabled  "  and  cut. 

Dwarf  varieties  are  short  enough  so  that  a  man  can 
easily  reach  the  heads ;  also,  the  base  of  the  brush  is 
inclosed  in  the  "  boot,"  which  must  be  removed.  When 
the  crop  is  uniform  enough  so  that  all  can  be  pulled  at  one 


CORN   CROPS 


time,  the  cheapest  way  is  to  pull  and  load  directly  on 
wagons.  When  it  must  be  pulled  twice,  that  harvested 
the  first  time  over  is  laid  on  the  ground  and  covered  with 
leaves.  It  is  not  possible  to  get  a  uniform  grade  in  this  way. 
Standard  broom-corn  is  first  "  tallied  "  and  the  heads 
are  then  cut  by  hand.  In  tabling,  one  man  passes  backward 


Fig.  118.  — Threshing  broom-corn  seed  heads  or  brush. 


between  two  rows,  bending  the  stalks  at  a  point  about 
30  inches  above  the  ground  toward  each  other  and  across 
the  row,  so  that  the  heads  hang  about  two  feet  past  the 
other  row.  Two  men  following  cut  off  the  heads  and 
place  them  evenly,  on  every  other  table.  Three  men  can 
harvest  about  two  acres  per  day.  Later,  a  team  with  a 
wagon  passes  over  the  empty  tables  and  the  brush  is 
collected. 

Threshing     and     storing.  —  The     heads    are    threshed 
directly  from  the  field,  or  within  a  very  few  days  after 


BROOM-CORN 


339 


cutting.  The  thresher  removes  all  seeds,  after  which  the 
brush  is  stored  in  drying  sheds,  in  thin  layers  about  3 
inches  deep. 

Bulking.  —  After  drying  for  about  three  weeks  the  brush 
is  piled  in  tiers,  called  ''  bulking,"  for  further  drying.     It 


Fig.  119.  —  Power  baling  press  for  broom-corn. 


then  goes  "  through  the  sweat,"  which  means  merely  that 
considerable  natural  heat  is  developed  and  the  drying  is 
hastened. 

Baling.  —  This  should  not  take  place  until  the  brush 
is  thoroughly  dried.  Good  bales  of  brush  are  often  very 
much  damaged  by  heating  and  molding,  as  a  result  of 
baling  before  dry.     A  bale  weights  300  to  400  pounds. 


340 


CORN  CROPS 


281.   Market  grades.  —  Certain  trade  terms  are  applied 
in  describing  the  qualities  of  broom-corn,  which  are  well 


Fig.  120.  — A  bale  of  broom-corn. 

understood  by  those  familiar  with  the  stock.  The  fol- 
lowing data,  prepared  by  C.  P.  Hartley,  give  trade  terms 
and  relative  prices  of  different  grades :  — 

Cents  per  Pound 

Fair,  crooked .  1^ 

Good,  well-handled,  crooked 2 

Fair,  medium,  red-tipped 3| 

Slightly  tipp  d,  smooth  growth  .......  4 

Good,  green    mooth,  self -working 4| 

Choice,  green,  self-working  carpet  stock  ....  5 

Fair,  medium,  sound  hurl        3^ 

Good  medium  hurl 4 

Good,  green,  smooth,  carpet  hurl 5 

Choice,  green,  smooth,  carpet  hurl 5| 


BBOOM-CORN 


341 


REFERENCES  ON  SORGHUMS 
Bureau  of  Plant  Industry,  United  States  Department  of  Agri- 
culture :  — 

Bulletin  50.     Three  Much  Misrepresented  Sorghums. 

Bulletin  175.     The  History  and  Distribution  of  Sorghums. 

Bulletin  203.     The  Importance  and  Improvement  of  Grain 
Sorghums. 

Bulletin  237.     Grain  Sorghum  Production  in  the  San  Antonio 
Region  of  Texas. 
Farmers'  Bulletins,  United  States  Department  of  Agriculture  :— 

Bulletin  37.     Kafir  Corn  Characteristics  and  Uses. 

Bulletin  50.     Sorghum  as  a  Forage  Crop. 

Bulletin  92.     Improvement  of  Sorghum. 

Bulletin  174.     Broom  Corn. 

Bulletin  246.     Saccharine  Sorghums  for  Forage. 

Bulletin  288.     Non-saccharine  Sorghums. 

Bulletin  322.     Milo  as  a  Dry  Land  Crop. 

Bulletin  334.     Sorghum  for  Silage. 

Bulletin  448.     Better  Grain  Sorghum  Crops. 

Bulletin  450.     The  Best  Two  Sweet  Sorghums  for  Forage. 

Bulletin  477.     Sorghum  Sirup  Manufacture. 
Kansas  Agricultural  Experiment  Station  Bulletins :  — 

Bulletin  23.     Smuts  of  Sorghum,  Corn  Smut. 

Bulletin  93.     Kafir   Corn. 

Bulletin  99.     (Page   5.)     Kafir  Corn,  Alfalfa  Hay,  and  Soy 


Beans  for  Pork. 
Bulletin  99.     (Page  32.) 
Bulletin  99.     (Page  35.) 

Corn. 
Bulletin  119. 
Bulletin  119. 
Bulletin  119, 


Kafir  Corn. 

Digestion  Experiments  with  Kafir 


Kafir  Corn  vs.  Good  Butter. 
Sorghum  Pasture  for  Dairy  Cows. 
Whole  Kafir  Corn  Compared  with 


(Page  28.) 
(Page  42.) 
(Page  63.) 
Ground  Kafir  Corn  for  Growing  Calves. 
Bulletin   136.     (Page   164.)     Sorghum  with   Corn  for  Baby 

Beef. 
Bulletin  136.     (Page  179.)     Kafir  Corn  Meal  and  Sorghum 

Seed  Meal  with  Soy  Bean  Meal  for  Swine. 
Bulletin  136.     (Page  202.)     Kafir  Corn  with  Alfalfa  for  Baby 
Beef. 


342  CORN   CROPS 

Bulletin  149.  Prevention  of  Sorghum  and  Kafir  Corn  Smut. 
Oklahoma  Agricultural  Experiment  Station  Bulletins  :  — 

Bulletin  22.     Field  Experiments  with  Kafir  Corn. 

Bulletin  35.  Summary  of  Digestion  Experiments  with  Kafir. 
Other  Bulletins:  — 

Florida  Agricultural  Experiment  Station,  Bulletin  92.  Sorghum 
for  Silage  and  Forage. 

Ohio  Agricultural  Experiment  Station,  Bulletin  21.     Sorghum. 

Georgia  Agricultural  Experiment  Station,  Bulletin  86.  Sor- 
ghum vs.  Corn  Meal  as  a  Source  of  Carbohydrates  for 
Dairy  Cattle. 

Iowa  Agricultural  Experiment  Station,  Bulletin  55.  Field 
Experiments  with  Sorghum. 

American  Breeders'  Association.  III.  Breeding  of  Grain 
Sorghums. 

Bureau  of  Entomology,  United  States  Department  of  Agri- 
culture, Bulletin  85.     The   Sorghum  Midge. 

South  Carolina  Agricultural  Experiment  Station,  Bulletin  88. 
Sorghum  as  a  Sirup  Plant. 

Nebraska  Agricultural  Experiment  Station,  Bulletin  77. 
Poisoning  of  Cattle  by  Corn  or  Sorghum,  and  Kafir  Corn. 

Texas  Agricultural  Experiment  Station,  Bulletin  99.  Kafir 
Corn  and  Milo  Maize  for  Fattening  Cattle. 

Colorado  Agricultural  Experiment  Station,  Bulletin  93. 
Colorado  Hays  and  Fodder. 

Texas  Agricultural  Experiment  Station,  Bulletin  13.  Sor- 
ghum ;  Value  as  Feed.     Effect  on  Soil. 

Ohio  Agricultural  Experiment  Station,  Bulletin  115.  Sugar 
Beet  and  Sorghum  Investigations  in  1899. 

Delaware  Agricultural  Experiment  Station,  Bulletin  44. 
Sorghum   in    1898. 

Delaware  Agricultural  Experiment  Station,  Bulletin  27. 
Tests  of  Sorghum  Varieties. 

New  Mexico  Agricultural  Experiment  Station,  Bulletin  33. 
Feeding  Non-saccharine  SorghumB. 


INDEX 


Acclimation,  117-121. 
Adaptation 

and  improvement  of  corn,  74. 

of  sorghuna  to  dry  climate,  288. 
Adjustment  of  corn  plants,  178. 
Air  passages,  35. 
Alkali  resistance,  290. 
Amber  sorghum,  297. 
Andropogon  halepensis,  279. 
Animal  and  insect  pests  of  corn,  214- 
221. 

Biological  origin,  16. 
Biotypes,  109. 
Breads,  252. 
Breeding 

close,  narrow,  broad,  102. 
Breeding  plants,  94. 

how  to  conduct,  95. 

notes,  97. 

selection  of  ears,  96. 
Broom  corn,  331-340. 

classification,  282. 

Carbon,  in  composition,  47. 
Chinch  bugs,  218. 
Chinese  maize,  24. 
Classification 

corn,  15,  20. 

by  groups,  20-24. 

broom  corn,  282, 

sorghum,  sweet,  281. 

sorghum,  non-saccharine,  282. 
Climatic  factors. 

in  growth  of  corn,  58-67. 

in  growth  of  sorghum,  288. 
Composition  of  corn,  42. 

as    affected   by  the  rote  planting, 
183. 

of  parts  of  plant,  184,  226. 

as  affected  by  time  of  cutting,  225. 


Composition  of  sorghums,  324. 
Corn 

binder,  234. 

cost  of  production,  247. 

crossing  biotypes.  111. 
varieties.  111. 

shows,  253. 
Corn  crop,  mineral  requirements  of, 

135. 
Coyote  corn,  20. 
Crossing  sorghums,  287. 

corn.  111. 
Crows,  214. 
Cultivation 

depth  and  frequency,  209. 

methods  compared,  206. 

principles  of,  197. 

tools  for,  198. 
Cultivators 

for  listed  corn,  202. 

two-row,  200. 
Cultural  methods,  158-275. 
Cutworms,  215. 

Dent  corn,  22. 
Description 

corn  plant,  26. 

sorghum  plant,  283. 
Development  of  varieties,  78. 
Diseases  of  corn,  220. 
Disk  harrow,  167. 
Dominant  characters,  105. 
Drainage,  157. 
Drought  resistance,  286. 
Drying  corn  for  shipment,  246. 
Durra,  299,  310. 

classification,  282. 

Ear 

origin,  37. 

proportion  of  plant,  228. 


343 


344 


INDEX 


Ear  {continued) 

relative  feeding  -^alue,  227. 

storage,  242. 

shrinkage,  245. 
Early  culture  of  corn,  77. 

methods  of  modifying,  80. 
Ear  worm,  218. 
Energy,  source  of,  47. 
Environment 

effect  on  corn,  118. 
Erosion,  154. 

causes  of,  155. 

prevention  of,  156. 
Euchlcena  Mexicana,  16. 
Evaporation  of  water,  151. 

from  soil  under  corn  crop,  208. 
Exportation  of  corn,  4. 

Fertilization  of  corn,  52. 

of  sorghum,  286. 
Fertilizers 

for  corn,  138. 

formulas,  142. 

increase  due  to,  141. 

use  in  rotation,  131. 

when  profitable,  144. 

with  farmyard  manure,  133. 
Flint  corn,  21. 

for  North  Carolina,  187. 

varieties,  189. 
Flowers  of  corn,  36. 
Fodder  shrinkage  in  curing,  243. 
Forage 

corn,  sowing  for,  171. 

yield  at  different  rates,  183. 

sorghum,  294. 

Gooseneck  sorghum,  300. 
Grain  sorghums,  301. 
Growth  of  corn,  48. 

climatic  factors,  58-67. 
length  of  growing  season,  59. 
relation  of  sunshine  to,  61. 
rainfall  to,  64. 
soils  to,  68. 
Growth  of  sorghum 

relation  of  climate  and  soils,  288- 
289. 
Grubworms,  216. 


Harshberger,  J.  L.,  15. 
Harvesting  corn,  222-248. 

breeding  plats,  97. 

comparative  cost  of  methods,  241. 

cost  of  harvesting  tops  and  leaves, 
232. 

time  of,  224. 
Harvesting  sorghum 

broom  corn,  337. 

for  forage,  322. 

for  grain,  319. 

for  sirup,  328. 
Hermaphrodite  forms,  24. 
History  of  corn,  see  Origin 

of  early  corn  culture,  77. 

of  sorghums,  279. 
Hoe  cake,  252. 
Hominy,  249. 
Husker  and  shredder,  238. 
Husking  fodder  corn,  237. 
Hybridization  of  corn,  101-116. 

Importation  of  corn,  6. 
Improvement  and  adaptation,  74-84. 

of  varieties,  85-92. 
Interculture,  principles  of,  197-213. 
International  trade  in  corn,  4. 

July  rainfall  and  yield,  66. 

Kafir,  309. 
Kowliang,  314. 

Leaves  of  corn,  33. 

composition  of,  184,  227. 

percentage,  226. 

stripping,  230. 

turgidity,  39. 
Lime,  147-149. 

application  of,  134. 

effect  of,  147. 
Lister,  168. 
Listing,  169. 

Manure,  farmyard 

for  corn,  130. 

value  the  ton,  132. 
Marketing,  245. 
Market  movement,  11. 


INDEX 


845 


Mass  selection,  88. 
results  with,  89. 
Meal,  corn,  249. 
Mendel's  laws,  104. 
Milo,  311. 

Mineral  matter  for  corn  soils,  135-150. 
Moisture  in  corn,  175. 

Natural  selection,  83. 
Nitrogen  for  corn,  134,  146. 
Non-saccharine  sorghums,  301. 

classification  of,  291. 

region  cultivated,  303. 

statistics,  304. 

Orange  sorghum,  298. 

Organic  matter  of  corn  soils,  130. 

Origin  of  corn 

biological,  16. 

geographical,  15. 
Origin  of  sorghum,  279. 

geographical,  280. 

Pasture  (sorghum),  325. 
Pedigree  selection  of  corn,  89. 
Physiology  of  corn,  38. 
Physiology  of  sorghum,  286. 
Plant,  corn 

description  of,  26-37. 

number  to  the  acre,  176. 

type  of,  86. 
Planter's  corn 

calibrating  planter  plates,  195. 

two-row  check,  172. 

lister,  168. 
Planting  corn,  161. 

checking  and  drilling,  172. 

depth  of,  175. 

rate  of,  176. 

on  various  soils,  180. 
time  of,  173. 
width  of  rows,  182. 
Plowing  for  corn,  163. 
Pod  corn,  20. 
Poisoning,  sorghum,  327. 
Poison,  for  squirrels,  215. 
Pop  corn,  21. 

products,  251. 
Preparation  of  land  for  corn,  161. 


Products,  corn,  249-251. 
Production,  broom  corn,  331. 
Production  of  corn 

as   related    to    climate    and    soils, 
54-73. 

causes  of  low,  70. 

continents,  2. 

countries,  2. 

development,  7. 

how  maintained,  134. 

percentage,  3. 

restoring,  123. 

United  States,  6. 

world's  crops,  1-2. 
Production    of    non-saccharine    sor- 
ghums, 304. 
Production  of  sorghum  sirup,  295. 

Rate  of  planting  corn,  176. 

on  different  soils,  180. 
Recessive  characters,  105. 
Relation  of  climatic  factors  to  growth, 
58. 

of  cropping  systems  to  yield,  122. 

of  July  rainfall  to  yield,  66. 

of  soils  to  growth,  68. 
Relationship,  degrees  of,  101. 
Relative  importance  of  corn,  1. 
Root  louse,  217. 
Roots  of  corn,  26—30. 

depth,  176. 

prevent  evaporation,  208. 

spread  of,  28. 
Roots  of  sorghum,  285. 

in  upper  layers,  290. 
Rootworm,  217. 
Rotations  for  corn,  127. 
Runoff  water,  151. 

Saccharine  sorghums,  293-300. 

classification,  296. 

introduction,  293. 

sirup,  first  grown  for,  294. 
gallons  produced,  295. 

sirup-making,  328-330. 
Seed  corn 

curing  sweet  corn,  264. 

germination  tests,  192. 

grading,  195. 


346 


INDEX 


Seed  corn  {continued) 

preparation  of,  190. 
Selection  of  corn 

for  composition,  91. 

mass,  88. 

natural,  83. 
Self-fertilization,  107. 
Shallu,  313. 
Shocks,  size  of,  235. 

tying,  237. 
Show  corn,  253-258. 
Shredding  fodder,  238. 
Shrinkage  of  ear  corn,  244. 

of  fodder  in  curing,  243. 

of  sUage,  243. 
Silage 

from  sorghum,  326. 

growing  corn  for,  212. 

shrinkage  of,  243. 

time  of  harvesting,  229. 
Sirup-making,  328-330. 
Smut  of  corn,  220. 
Soft  corn,  22. 
Soils 

as  related  to  growth,  68. 

classification  of  corn  soils,  70. 

non-saccharine  sorghums,  301. 

saccharine  sorghums,  293. 
Sowing  corn  for  forage,  171. 
Squirrels,  214. 
Stalk  cutter,  162. 
Stomata,  number,  35. 
Stover,  feeding  value  of,  229. 

relative  yield,  228. 
Style,  51. 
Subsoiling,  166. 
Sunlight,  intensity  of,  62. 
Sweet  corn 

contract  with  growers,  266. 

description  of,  22. 

forcing  sweet  corn,  273. 

market  for,  270. 

products  of,  251. 

seed,  263. 

varieties,  262. 

Teosinte,  18. 
Tillage 

comparison  of  methods,  206. 


depth  and  frequency,  209. 

machinery,  197. 

reasons  for,  205. 
Tillers,  33. 

economic  value  of,  179. 

factors  effecting,  179. 
Tripsacmn  dactyloides,  16. 
Tull,  Jethro,  205. 
Types  of  corn  for  different  sections, 

185. 
Type  of  ear,  85. 
Type  of  plant,  86. 

Uses  of  corn,  249-252. 

Utilizing  the  sorghum  crop,  324. 

Value  of  principal  crops,  7. 
Varieties  of  corn 

development  of,  78. 

for  different  regions,  187. 

improvement,  85. 

production  by  selection,  83. 
Varieties  of  sorghum 

broom  corn,  331. 

for  grain,  301. 

sweet  sorghums,  293. 

Water 

absorption,  45. 

given  off,  45. 

loss  from  fallow  soil,  207. 

loss  of,  35. 

regulating  supply  of,  151-157. 

required  by  months,  152. 

required  for  corn,  65,  151. 
Weeds 

clearing,  168. 

effect  on  yield  of  corn,  208. 
Wireworms,  216. 

Xenia,  103. 

Yields,  corn. 

ability  of  corn  to,  57. 
relation  to  cropping  system,  122. 
to  the  acre,  7. 
to  the  acre,  forage,  183. 
when  harvested  at  different  dates, 
224. 


INDEX 


347 


Yields,  sorghum 
broom  corn,  331. 
forage,  323. 
grain,  320. 
sirup,  329. 

Zea  Mays 
amylacea,  22. 
canina,  20. 


curagua,  24. 
everta,  21. 
hirta,  23. 
indentata,  22. 
indurata,  21. 
japonica,  23. 
saccharata,  22, 
tunicata,  20. 


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stood by  farmers.  Nor  do  those  who  understand  the  application  of  such 
principles  to  city  conditions  often  know  how  to  apply  them  on  the  farm. 

"  Long  ages  of  experience  and  a  generation  of  scientific  research  have 
resulted  in  a  fund  of  popular  knowledge  on  how  to  raise  crops  and  animals. 
But  there  is  less  background  of  tradition  concerning  business  methods  on 
the  farm,  and  colleges  have  given  little  attention  to  this  kind  of  problem. 
The  success  of  the  individual  farmer  is  as  much  dependent  on  the  applica- 
tion of  business  principles  as  it  is  on  crop  yields  and  production  of  animals. 

"  The  best  way  to  find  out  what  methods  of  farm  organization  and  man- 
agement are  most  successful  is  to  study  the  methods  now  used  and  the 
profits  secured  on  large  numbers  of  farms,  and  determine  how  the  more 
successful  ones  differ  from  the  less  successful,  and  find  to  which  of  the 
differences  the  success  is  due.  After  such  principles  are  found,  they  need 
to  be  tested  by  use  in  reorganizing  farms. 

"  The  conclusions  in  this  book  are  based  on  investigations  of  the  kind 
given  above,  and  on  cost  accounts,  census  data,  travel  and  study  in  differ- 
ent parts  of  the  United  States  and  experience  in  farming.  It  is  hoped  that 
the  conclusions  may  be  of  use  to  farmers  and  students." — -Preface* 


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NEWEST  ADDITIONS  TO   THE  RURAL  SCIENCE  SERIES 

Edited  by  Professor  L.  H.  BAILEY,  Director  of  the  New  York 
State  School  of  Agriculture  at  Cornell  University- 


Sheep  Farming 

By  JOHN   A.  CRAIG  and  F.  R.  MARSHALL 

Illustrated.     Cloth,  i2mo,  $1.50 

This  book  deals  with  sheep  husbandry  as  a  phase  of  intensive  farming. 
Recognizing  that  it  is  likely  to  be  used  by  persons  unfamiliar  with  sheep, 
the  authors  have  worked  from  the  standpoint  of  the  producer  of  the  market 
stock  rather  than  from  the  standpoint  of  the  professional  breeder.  The 
various  breeds  are  discussed  in  such  a  way  as  to  enable  the  reader  to  select 
the  kind  that  is  most  likely  to  do  well  under  his  conditions  and  to  acquaint 
him  with  the  care  it  is  accustomed  to  and  needs.  The  management  of  the 
flock  in  the  fall,  winter,  spring,  and  summer  seasons,  the  formation  of  the 
flock,  the  selection  of  foundation  stock,  and  the  means  of  maintaining  a 
high  standard  of  flock  efficiency  are  all  discussed  in  subsequent  chapters. 

Principles  of  Fruit  Growing 

By  Professor  L.  H.  BAILEY 

New  edition.     Cloth,  i2mo,  $1.30 

Since  the  original  publication  of  this  book,  in  1897,  it  has  gone  through 
many  editions.  The  progress  of  fruit  growing  in  the  meantime  has  been 
very  marked  and  it  has  been  necessary  to  completely  rewrite  the  work. 
The  present  issue  of  it  brings  the  accounts  of  the  new  practices  and  discov- 
eries as  they  relate  to  fruit  growing  up  to  date.  All  of  the  text  and  practi- 
cally all  of  the  illustrations  are  new. 


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RURAL  SCIENCE  SERIES  —  Continued 

Cooperation  in  Agriculture 

By  G.  HAROLD   POWELL 

Illustrated.      Cloth,  i2mo,  $/.^0 

This  book  deals  with  the  general  principles  of  cooperation.  How  to 
organize  cooperative  societies,  how  to  finance  them,  simple  organizations 
and  constitutional  documents,  by-laws,  and  general  advice  as  to  the  admin- 
istration of  the  associations  or  societies  are  all  considered.  The  author 
describes  at  some  length  the  most  famous  organizations,  such  as  those 
which  are  handling  citrus  fruits  in  California,  the  farmers'  grain  elevators 
systems,  and  the  present  cooperation  in  the  creamery  and  butter  business. 
It  is,  in  other  words,  a  practical  guide  for  those  who  desire  to  organize 
cooperative  societies  and  who  wish  to  escape  the  usual  pitfalls. 

Farm  Forestry 

By  E.  G.  CHEYNEY 

Illustrated.     Cloth,  i2mo,  $r.^o 

This  book  deals  with  the  place  of  the  wood  lot  or  farm  forest  in  the  scheme 
of  farming,  with  the  planting,  care,  and  harvesting  of  timber  on  lands,  with 
the  different  species  of  trees  that  may  be  used,  their  relations  or  associa- 
tions in  a  forest  plantation,  the  rate  of  growth,  the  profits  to  be  expected 
and  the  principal  difficulties  that  are  usually  encountered.  It  is  profusely 
illustrated. 

Forage  Crops  for  the  South 

By  S.  M.  TRACY 

Illustrated.     Cloth,  i2mo,  $i.^o 

Professor  Tracy  has  had  long  experience  in  Southern  agriculture,  both  in 
application  and  in  teaching.  He  was  formerly  Professor  of  Agriculture  in 
the  Mississippi  Agricultural  College,  and  now  conducts  a  branch  station  or 
farm  for  the  United  States  Department  of  Agriculture.  He  is  a  botanist  of 
note  and  has  traveled  extensively  in  the  South  as  a  collector.  His  book  is 
not  only  authentic,  but  practical.  In  it  is  contained  a  discussion  of  all 
kinds  of  plants  and  crops  adapted  to  the  Southern  States  for  fodder,  soiling, 
pasturing,  and  hay.    The  text  is  abundantly  illustrated. 


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Fruit  Insects 

By  M.   V.   SLINGERLAND  and  C.    R.   CROSBY 

Illustrated,  cloth,  i2mo,  %i.^o 

This  is  a  practical  account  of  the  principal  insects  in  this  coun- 
try which  attack  the  diflferent  i^inds  of  fruits  —  trees,  fruits, 
small  fruits,  cranberries,  grapes,  and  the  like.  It  presents  a 
full  but  brief  outline  life  history  of  the  leading  insects  together 
with  the  methods  of  control. 

Milk  and  Its  Products 

By  henry   H.   wing 

Professor  of  Dairy  Husbandry  in  Cornell  University 
Nezu  Revised  Edition,  with  new  illustrations,  cloth,  i2mo,  $i.^o 

The  revolution  in  dairy  practice,  brought  about  by  the  introduc- 
tion of  the  centrifugal  cream  separator  and  the  Babcock  test  for 
fat,  by  a  more  definite  knowledge  regarding  the  various  fermen- 
tations that  so  greatly  influence  milk,  and  the  manufacture  of  its 
products,  have  demanded  the  publication  of  a  book  that  shall 
give  to  the  dairyman,  and  particularly  to  the  dairy  student,  in 
simple,  concise  form,  the  principles  underlying  modern  dairy 
practice.  Such  has  been  Professor  Wing's  purpose  in  this 
work.  This  is  not  a  new  edition  of  the  author's  very  successful 
volume  published  under  the  same  title  many  years  ago  ;  it  is,  in 
reality,  an  entirely  new  book,  having  been  wholly  reset  and  en- 
larged by  the  addition  of  new  matter,  both  text  and  illustra- 
tions. The  author's  aim  has  been  at  all  times  to  give  the  pres- 
ent state  of  knowledge  as  supported  by  the  weight  of  evidence 
and  the  opinions  of  those  whose  authority  is  highest. 


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OF  KINDRED  INTEREST 


The  Farmer  of  To-morrow 

By   F.    I.    ANDERSON  Cloth,  i2mo,  $r.so 

There  has  been  a  great  deal  of  theorizing  about  the  "  back  to 
the  land  "  movement.  It  is  the  purpose  of  this  book  to  crystal- 
lize and  to  make  practical  all  of  the  vague  generalizations  which 
have  so  far  been  expressed  on  this  subject.  To  this  end  the 
first  part  of  Mr.  Anderson's  book  is  given  over  to  a  considera- 
tion of  the  land  itself  as  a  factor  in  the  movement,  primarily  its 
economic  bearing  on  the  question.  The  second  half  takes  up 
the  soil  with  a  detailed  exposition  of  soil  sanitation,  the  author 
confining  himself,  however,  to  only  the  broad  principles.  In 
presenting  these  two  main  thoughts  the  author  touches  upon 
such  important  and  interesting  topics  as  Why  Europe  Raises 
Three  Bushels  of  Grain  to  Our  One,  Why  Soils  Become  Un- 
productive, Why  the  Farmer  of  Yesterday  is  Rich,  Why  There 
Has  Been  No  Increase  in  Acreage  Productivity,  and  Why  Irri- 
gated Land  Pays  Interest  on  a  Capitahzation  of  Two  Thousand 
Dollars  an  Acre.  The  book  is  one  which  should  be  of  interest 
alike  to  those  who  are  actively  engaged  in  some  form  of  agricul- 
ture and  to  those  who  are  trying  to  solve  the  problem  of  the 
high  cost  of  living. 

Malaria  :    Cause  and  Control 

By   WILLIAM    B.    HERMS  Illustrated,  cloth,  8vo,  $1.^0 

The  awakening  of  the  general  public  to  the  necessity  and  possi- 
bility of  the  control  of  malaria,  indicated  by  the  incessant  de- 
mand for  information,  makes  the  publication  of  Professor 
Herms's  concise  treatment  of  the  subject  an  important  and 
timely  event.  The  question  of  malaria  control  is  deserving  of 
the  most  careful  attention,  particularly  in  tliese  days  w^hen  so 
much  is  heard  of  the  "  back  to  the  soil "  movement.  For  ma- 
laria is  notably  a  disease  of  rural  districts.  Those  who  are 
familiar  with  the  situation  know  very  well  that  malaria  is  too 
often  responsible  for  farm  desertion.  Professor  Herms  writes 
of  the  conditions  attending  the  disease  as  he  has  found  and 
studied  them  during  the  past  few  years  himself,  and  the  sugges- 
tions for  control  which  he  makes  are  such  as  he  has  applied  and 
found  successful. 

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Warren's  Elements  of  Agriculture 

By  G.  F.  WARREN,  Professor  of  Farm  Management  and 
Farm  Crops,  New  York  State  College  of  Agriculture  at  Cor- 
nell University 

Cloth,  127710,  4^6  pages,  $i.io 

Written  by  Professor  G.  F.  Warren,  who  is  in  charge  of  the  Department  of 
Farm  Management  and  Farm  Crops  in  the  New  York  State  College  of  Agri- 
cuhure,  Cornell  University,  an  authority  on  questions  pertaining  to  practical 
agriculture. 

Professor  Warren  is,  moreover,  a  farmer.  He  grew  up  on  a  farm  in  the  mid- 
dle West  and  is  living  at  the  present  time  on  a  farm  of  three  hundred  and 
eighteen  acres,  which  he  supervises  in  connection  with  his  work  at  the  Univer- 
sity. 

The  "  Elements  of  Agriculture  "  is  a  text  that  does  not  "  talk  down  "  to  the 
pupil.  It  gives  agriculture  rank  beside  physics,  mathematics,  and  the  languages, 
as  a  dignified  subject  for  the  course  of  study. 

In  Warren's  "  Elements  of  Agriculture  "  there  is  no  waste  space.  It  is  writ- 
ten with  the  ease  that  characterizes  a  writer  at  home  in  his  subject,  and  it  is 
written  in  a  style  pedagogically  correct.  The  author  has  been  a  teacher  of  high 
school  boys  and  girls  and  knows  how  to  present  his  subject  to  them. 

Experts  in  the  teaching  of  agriculture  the  country  over  have  been  unanimous 
in  praise  of  the  text.     For  instance : 

Mr.  J.  E.  Blair,  Supt.  of  Schools,  Corsicana,  Texas  : 

"An  examination  of  Warren's  '  Elements  of  Agriculture'  convinces  me  that 
it  is  a  book  of  uncommon  merit  for  secondary  schools  as  well  as  for  the  private 
student.  It  is  thoroughly  scientific  in  matter,  and  is  written  in  an  attractive 
style,  that  cannot  fail  to  please  as  well  as  instruct." 

Supt.  E.  S.  Smith,  Whiti7ig,  Iowa  : 

"  I  am  very  much  pleased  with  Warren's  '  Elements  of  Agriculture.'  In  my 
opinion  it  is  the  only  book  on  the  market  that  presents  the  work  of  agriculture 
suitably  for  high  schools ;  too  many  books  are  too  simple  and  do  not  give 
enough  work ;  a  book  for  high  schools  must  be  more  than  a  primer." 


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RURAL  SCIENCE  SERIES 

Edited  by  L.  H.  BAILEY 


On  Selection  of  Land,  etc. 

Isaac  P.  Roberts'  The  Farmstead $1  50 

On  Tillage,  etc. 

F.  H.  King's  The  Soil 1  50 

Isaac  P.  Roberts'  The  Fertility  of  the  Land         ...  1  50 

F.  H.  King's  Irrigation  and  Drainage 1  50 

Edward  B.  Voorhees'  Fertilizers 1  25 

Edward  B.  Voorhees'  Forage  Crops 1  50 

J.  A.  Widtsoe's  Dry  Farming 1  50 

L.  H.  Bailey's  Principles  of  Agriculture         ....  1  25 

On  Plant  Diseases,  etc. 

E.  C.  Lodeman's  The  Spraying  of  Plants      ....  1  85 

On  Garden-Making 

L.  H.  Bailey's  Garden-Making 1  50 

L.  H.  Bailey's  Vegetable-Gardening 1  50 

L.  H.  Bailey's  Forcing  Book 1  25 

On  Fruit-Growing,  etc. 

L.  H.  Bailey's  Nursery  Book 1  50 

L.  H.  Bailey's  Fruit-Growing  .......  1  50 

L.  H.  Bailey's  The  Pruning  Book 1  50 

F.  W.  Card's  Bush  Fruits .  1  50 

On  the  Care  of  Live-stock 

Nelson  S.  Mayo's  The  Diseases  of  Animals  ....  1  50 

W.  H.  Jordan's  The  Feeding  of  Animals       ....  1  50 

I.  P.  Roberts'  The  Horse 1  25 

M.  W.  Harper's  Breaking  and  Training  of  Horses       .        .  1  50 

George  C.  Watson's  Farm  Poultry 1  25 

On  Dairy  Work,  Farm  Chemistry,  etc. 

Henry  H.  Wing's  Milk  and  Its  Products       ....  1  50 

J.  G.  Lipman's  Bacteria  and  Country  Life   ....  1  50 

On  Economics  and  Organization 

I.  P.  Roberts'  The  Farmer's  Business  Handbook         .        .  1  25 

George  T.  Fairchild's  Rural  Wealth  and  Welfare         .        .  1  25 

H.  N.  Ogden's  Rural  Hygiene .  1  50 

J.  Green's  Law  for  the  American  Farmer      ....  1  50 


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Cyclopedia  of  American  Agriculture 


Edited  by  L.  H.  BAILEY 

?riculture  and  Prof 
;jornell  University. 


Director  of  the  College  of  Agriculture  and  Professor  of  Rurai  Economy, 
Cc       ■■  "  ■ 


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in  the  text;  four  volumes;  the  set,  $20.00  half  morocco, 

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Volume  I— Farms         Volume  III— Animals 

VOLUME  II— Crops  Volume  rv— The  Farm  and  the  Community 

"Indispensable  to  public  and  reference  libraries  ...  readily 
comprehensible  to  any  person  of  average  education." — The  Nation. 

"The  completest  existing  thesaurus  of  up-to-date  facts  and  opinions 
on  modern  agricultural  methods.  It  is  safe  to  say  that  many  years 
must  pass  before  it  can  be  surpassed  in  comprehensiveness,  accuracy, 
practical  value,  and  mechanical  excellence.  It  ought  to  be  in  every 
library  in  the  country." — Record-Herald,  Chicago. 


Cyclopedia  of  American  Horticulture 

Edited  by  L.  H.  BAILEY 

With  over  2,800  original  engravings;  four  volumes;  the  set, 
$20.00  half  morocco,  $32.00  carriage  extra 

"This  really  monumental  performance  will  take  rank  as  a  standard 
in  its  class.  Illustrations  and  text  are  admirable.  .  .  .  Our  own 
conviction  is  that  while  the  future  may  bring  forth  amplified  editions 
of  the  work,  it  will  probably  never  be  superseded.  Recognizing 
its  importance,  the  publishers  have  given  it  faultless  form.  The 
typography  leaves  nothing  to  be  desired,  the  paper  is  calculated  to 
stand  wear  and  tear,  and  the  work  is  at  once  handsomely  and 
attractively  bound." — New  York  Daily  Tribune. 


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